New top three: 1. Contador, 2. Aru +2, 3. Porte +20. So, just two seconds in it... perfectly poised for us spectators.
La Spezia - Abetone
Giro d'Italia - 13 May 2015
Giro d'Italia – Follow this cycling race live with Eurosport. The action starts at 19:05 on 13 May 2015. Our live coverage lets you follow all the key moments as they happen.
Get all the latest on Cycling: the big races, schedules and results.
So that's a four-second bonus for Aru, which is a small victory but a victory nonetheless. Contador takes over the pink jersey from Orica-GreenEdge though. Time splits coming up.
Chavanel just holds on for second place - by half a bike - as Aru mops up the final bonus seconds for third place ahead of Contador and Porte. What a finale.
Sylvain Chavanel will take second place. Dillier and Domont appear to have been caught. The IAM rider is almost there - just as Aru attacks behind...
His mouth agape, Jan Polanc roars onto the final straight before crossing the line with his arms aloft. Victory for the 23-year-old Slovenian!
Polanc can almost taste the victory now as he approaches the finish straight...
Ryder Hesjedal also has a pop - yet again, this is a mere aside to the main events.
Giovanni Visconti attacks from the pack - but that's just a detail.
Movistar are leading the chase in the 'pack' with no sign of Uran as yet. Meanwhile, Polanc is riding to a first professional win. Chavanel has yet been caught by the Aru group.
Polanc is out of the saddle and grimacing with intent as he rides towards the 2-to-go banner. He's still in the big ring - and has 1:45 over the chasing group, who have a whole minute over the Uran group.
Rigoberto Uran the big loser again today - he just cannot match the explosiveness of Porte, Aru and Contador.
Advantage Astana: Landa manages to catch the big three, so Aru now has a team-mate with him. With Chaves dropped, Contador is now the virtual maglia rosa.
Porte and Aru have caught Contador, who's out of the saddle and in the big ring. They catch Domont under the 5-to-go banner - and then Porte has a dig! The gap for Polanc is just two minutes now - or 1km.
ATTACK: Alberto Contador jumps on the pedals! Aru and Porte respond, but they're a few bike lengths back...
It's Paolo Tiralongo riding hard on the front for Astana, who have cut the gap to three minutes. The peloton has been whittled down to about 40 riders now. Siutsou is with Porte now.
Astana now on the front of this climb - but it's not steep enough for any big attacks it seems. Carlos Betancur of Ag2R-La Mondiale has been dropped - as has Simon Clarke, the pink jersey.
Another attack from Pirazzi! The Italian is indefatigable. Polanc is now in the forest section, and he has 3:30 over the pack. Pirazzi catches Tvetcov, but the pair are then swept up by the peloton.
Landa and Pirazzi have been caught by the peloton, which is being led by Tinkoff-Saxo. Porte is isolated, with just one team-mate a few riders behind.
Chavanel has definitely distanced Dillier, but he's struggling out of the saddle now. He's about 30 seconds down on lone leader Polanc.
Another attack by Astana, who send Mikel Landa up the road. The Spaniard catches Pirazzi. Up ahead, Polanc is now on the 10% section.
This is Polanc's second Giro d'Italia and he has never finished a stage higher than 4th position. The 23-year-old has no professional wins to his name - yet.
Astana launch an attack through Tanel Kangert, but Tinkoff-Saxo veteran Ivan Basso chases it down. Now it's the turn of Stefano Pirazzi of Bardiani-CSF, who opens up a slight gap.
Porte has a team-mate now. It looks like Henao. Chavanel is in the big ring and has dropped Dillier as he chases down Polanc.
Polanc is holding the gap now - it's four minutes for the Lampre-Medira rider, who finally has a team car behind him. He has 20 seconds on the two chasers, Chavanel and Dillier. He's about to hit the hardest 10% segment of the climb.
Slovenian Jan Polanc (Lampre-Merida) has dropped both Silvans/Sylvains and is the lone leader. Back in the pack, it's Astana and Tinkoff-Saxo on the front, and Richie Porte seems to be isolated. He has no Sky riders around him for now...
A huge dig by Polanc drags Chavanel back to the Dillier, so we have the three riders together again. It appears that Domont has been caught and passed, because these three riders are now leading the race. They have four minutes over the peloton.
Domont and Polanc fight back on - and then Domont, the Ag2R-La Mondiale ride - puts in a stealth attack. Dillier rides in pursuit, but both Chavanel and Polanc are on the rivet.
Another attack from Chavanel, the wily French veteran. Domont and Polanc are distanced, but Dillier can follow. It's a tale of two Silvans/Sylvains now.
All nine Tinkoff-Saxo riders have come to the front now for Contador...
ATTACK: Chavanel makes the first dig on this climb, taking Dillier with him. Tvetcov shakes his head - he has no juice left in the tank - and the Russian is dropped. Domont and Polanc are able to fight back on, so just four in the lead now. The gap is 4:50.
Five GreenEdge riders - including pink jersey Simon Clarke and white jersey Esteban Chaves - on the front, with Pieter Weening setting the pace.
Orica-GreenEdge are back on the front of the peloton, which is about to hit the start of the climb. The gap is down to 5:40 for the five leaders, so it's not guaranteed.
Front wheel puncture for Team Sky's Mikel Nieve, who will need to fight back onto the peloton ahead of the climb - while the leaders are on it, the pack are just doing that final downhill segment before the road heads up. Not ideal for Nieve, who is one of Richie Porte's key mountains lieutenant.
We're onto the final 17.3km Cat.2 climb to Abetone - which has an average gradient of 5.4% and a maximum gradient of 10%. The top is 1386 metres high - and a popular ski resort in the winter. The hardest segment comes halfway up with 8km remaining.
The leaders are on a short downhill ahead of the official start of the final climb to Abetone. The gap is now 6:35 so it's coming down pretty fast.
A solitary CCC Sprandi rider edges clear of the Tinkoff-Saxo-led peloton but he was just stretching his legs. Contador's team have taken up the tempo from Orica-GreenEdge now. It's about to be showtime. Eight minutes the gap for Chavanel, Polanc, Domont, Tvetcov and Dillier.
Although the road has been edging uphill since Bagni di Lucca, the climb proper has yet to begin. It will do so in about 5km. The gap is down to eight minutes for the break. They should hold on - unless it's utter devastation behind.
The gap down to 8:25 now. It's coming down, but will it come down enough to deprive one of these five leaders a memorable stage win? All will be revealed inside the next 45 minutes or so.
A smiling Richie Porte (Team Sky) is riding alongside a very serious-looking Fabio Aru (Astana). Porte has been in super form this year, winning the Tour of Catalunya, Paris-Nice and the Giro del Trentino. But it was Aru who lit the torch paper yesterday with his attack on the final climb - despite the Italian youngster being ill in the lead-up to the race. You sense that those two, and Contador, will finish together today - but Rigoberto Uran may try and steal some time back.
It's the calm before the storm as the road starts to edge uphill a little. A few more teams have come to the front now alongside Orica-GreenEdge. You sense that FDJ may try something through Geniez or Elissonde. Vini-Fantini are there too for Damiano Cunego. The gap is down to 9:20.
FLASHPOINT: Alberto Contador changes his bike and is now being ushered back to the peloton by a couple of Tinkoff-Saxo team-mates. Your guess is as good as mine as to whether that was intentional - but Contador does have a track record of changing steeds mid-race.
More refuelling for the break, as Serghei Tvetcov reaches round for an energy bar. The gap is down to 9:40 now as GreenEdge up the tempo a little.
The five leaders approach the second intermediate sprint at Bagni di Lucca. They still have over 10 minutes on the peloton - provided the GPS of the host broadcaster is correct (there are suggestions that yesterday they over-exaggerated the break somewhat, hence the speed at which the gap came down).
Elia Viviani is picking up some bidons for his Sky team-mates, stuffing them down his red jersey with more gusto than Mark Cavendish did with his rainbow stripes back in 2012. Meanwhile, another former Sky rider, Simon Gerrans, is munching on some food - either an energy bar, sandwich or banana. It's hard to tell. We didn't see it going in, just his frantic mastication.
No change as the riders continue the gradual descent towards Bagni di Lucca, where the toad will start to head up ahead of the final ascent to Abetone. The gap is 10:25 for the five leaders, with Orica-GreenEdge still controlling things on the front of the peloton. It's fair to say, today's stage doesn't have a fraction fo the excitement on offer yesterday - fo now.
Tvetcov has managed to catch the other escapees up, but he has a problem with his left shoe - the binding strap snapped off when he unclipped at speed to steady himself. He draws level with his Androni team car, is promptly told there's no spare shoes by silver fox DS Gianni Savio, and is then taped up by a mechanic. It's a quick fix, but it'll have to do.
Perhaps the intermediate sprint has gone to his head, because Tvetcov then overcooks a hairpin bend on the descent from Barga and almost comes off his bike. Replays show that he was probably confused with a road intersection and took the turning instead of continuing the bend. He then rode it out onto the grass verge so as not to make a sudden skid, which would have no doubt seen him hit the deck. Good evasive action from the Russian, who was leading the five man break there. Luckily, none of the other escapees followed his line.
The leaders are negotiating the short but sharp-ish climb up to the town of Barga, where the first of two intermediate sprints comes. It's uncontested, with Russia's Serghei Tvetcov (Androni) taking maximum points and bonus seconds. Back with the peloton, the Orica-GreenEdge pace-setters are tucking into their feedzone musettes.
The gap is 10:35 for the five leaders, so it looks like one of them will win the stage today - even if all hell breaks loose behind. We've got the two intermediate TV sprints coming up - but none of these riders is a threat to the current maglia rossa - red jersey - of Elia Viviani, the winner of stage two from Team Sky.
Both Axel Domont and Silvan Dillier have been involved in breaks so far in this race, while Sylvain Chavanel came down in that first crash involving IAM team-mate Heinrich Haussler back in stage two. Alessandro Malaguti has finally called it a day, the Nippo-Vini Fantini rider sitting up and allowing himself to be swallowed up by the peloton.
The five leaders are entering the town of Castelnuovo di Garfagnana which is where today's feed zone is. The whole peloton should consider themselves lucky: two routes out of town include the barbaric climb to San Pellegrino in Alpe and the less steep but longer sinuous ascent of the Passo delle Radici. The route today, however, continues down the valley towards Bagni di Lucca before heading up towards the ski resort of Abetone. In short: today's stage could have been so much harder.
The gap is up to 10 minutes for the five leaders, who are: Axel Domont (Ag2R-La Mondiale), Serghei Tvetcov (Androni Sidermec), Silvan Dillier (BMC), Sylvain Chavanel (IAM) and Jan Polanc (Lampre-Merida). They broke clear about 10km into today's 152km stage. The best placed on GC is Polanc, currently 19:19 down, and so somewhat short of being the virtual maglia rosa...
You have to feel for Alessandro Malaguti - he's been riding on his own pretty much the entire stage, and managed to get as close as two minutes to the break. But he's now four minutes back, but five minutes ahead of the peloton. Surely he calls it a day and sits up?
Orica-GreenEdge are still leading the chase - and tonight they could perhaps have a fourth rider in pink: Esteban Chaves. It all depends on whether or not the Colombian can stick with the big guns on today's final climb to Abetone.
The five leaders have crested the summit with a nine minute lead over the peloton, with lone ranger Malaguti still toiling away three minutes in arrears.
What a great race so far from Orica-GreenEdge, who have now had three different Australian riders in the pink jersey since that opening day team time trial win in San Remo: Simon Gerrans, Michael Matthews and Simon Clarke. Don't forget Matthews' stage three win, plus Esteban Chaves's white jersey - the Colombian, currently second place at 10 seconds behind his team-mate Clarke - is the best placed young rider.
The Cat.3 climb to Foce Carpinelli is 10km long at 5%. The five leaders are now about half way up, with a gap of 2:30 over lone chaser Malaguti, who himself is over five minutes ahead of the peloton.
There's no threat from any of these escapees for the race favourites: the highest place on GC is Slovenia's Jan Polanc of Lampre-Merida, who is almost 20 minutes down.
One rider - Alessandro Malaguti Nippo - Vini Fantini) - is riding 'chasse patate' in between the break and the peloton. He's about four minutes down on the leaders and one minute ahead of the pack, taking advantage of the relatively slow pace after yesterday's fast and furious stage.
The five escapees saw their lead extend to five minutes as that first climb to Foce Carpinelli loomed, with the Orica-GreenEdge team-mates of pink jersey Simon Clarke setting the pace on the front of the pack.
Astana really took the race by the scruff of its neck yesterday, chasing down the leading group and setting such a high tempo that Alberto Contador was left with no team-mates after Mick Rogers finally cracked. After Fabio Aru attacked, only Contador and Richie Porte could follow. The Spaniard could call on Roman Kreuziger, who was - oddly - involved in the large break. Rigoberto Uran of Etixx lost 42 seconds to his rivals.
An early attack came from a group of five riders: Axel Domont (Ag2R-La Mondiale), Serghei Tvetcov (Androni Sidermec), Silvan Dillier (BMC), Sylvain Chavanel (IAM) and Jan Polanc (Lampre-Merida). They quickly built up a lead of two minutes over the peloton.
The remaining 191 riders rolled out of La Spezia at 12:15 UK time. Two withdrawals yesterday: Gianni Meersman (Etixx-QuickStep) and Robert Wagner (LottoNL-Jumbo).
What a stage we had yesterday, with Italian youngster Davide Formolo holding onto the win despite the race's big guns battling it out on the third and final climb of the day. Read all about it in yesterday's report below...
The five stage of this compelling 98th edition of the Giro is a 152km slog into the Apennines - passing closely to Oleg Tinkov's summer Italian Tuscan retreat at Lido di Camaiore. There are two categorised climbs, including the Cat.2 ascent to Abetone - the hardest of the race so far.
Hello and welcome to live coverage of stage 5 of the Giro d'Italia. It's the first mountaintop finish as the riders head to the Apennine ski resort of Abetone for what could be a thrilling finale.