After Biaggi had crashed in race one in France, Sykes knew that if he won the second race Biaggi - who had struggled all weekend at Magny Cours - would need to finish fifth or better to hold him off in the final standings.
And though Sykes won the race by nearly two seconds from Jonathan Rea, Biaggi clinched the fifth place he needed to win the championships by just half a point.
Marco Melandri also started the final race with a chance of winning the title if both Biaggi and Sykes ran into problems, but he crashed out early on to see his hopes evaporate.
"This is the fourth world championship out of six that I have won at the final race, I seem to like difficult challenges," said Biaggi after coming out on the right side of the closest ever finish to a season.
"The 2012 season went right down to the wire: we started well with a win at Phillip Island after totally renewing my team and we also had some difficult moments. We had to work hard to win the title, and maybe for this reason it’s even better."
Sykes tried to remain positive despite his obvious disappointment.
"It’s difficult to accept that half a point separates us in a full season, but that’s all credit to World Superbike and how close it is," he said.
"Max did a great job, but for me and my season I’m very happy, everyone gave me a full package to do something with and this weekend I was very strong. Overall we had a pole position, circuit record, two podiums and I’d like to dedicate that to Joan Lascorz, I’ve had some help from him this weekend. To close 30 points on Biaggi was magical."
1. Maxi Biaggi - APRILIA - 358
2. Tom Sykes - KAWASAKI- 357.5
3. Marco Melandri - BMW - 328.5
4. Carlos Checa - DUCATI - 287.5
5. Jonathan Rea - HONDA - 278.5
Race two results
1. Tom Sykes (Kawasaki Racing Team) Kawasaki ZX-10R 38'15.725
2. Jonathan Rea (Honda World Superbike Team) Honda CBR1000RR 38'17.079
3. Sylvain Guintoli (PATA Racing Team) Ducati 1098R 38'18.118
4. Eugene Laverty (Aprilia Racing Team) Aprilia RSV4 Factory 38'28.847
5. Max Biaggi (Aprilia Racing Team) Aprilia RSV4 Factory 38'29.680
6. Davide Giugliano (Althea Racing) Ducati 1098R 38'33.954
7. Carlos Checa (Althea Racing) Ducati 1098R 38'34.155
8. Chaz Davies (ParkinGO MTC Racing) Aprilia RSV4 Factory 38'42.373
9. Ayrton Badovini (BMW Motorrad Italia GoldBet) BMW S1000 RR 38'49.534
10. Leon Camier (FIXI Crescent Suzuki) Suzuki GSX-R1000 38'52.942
11. Maxime Berger (Red Devils Roma) Ducati 1098R 38'54.596
12. Claudio Corti (Team Pedercini) Kawasaki ZX-10R 39'11.439
13. Lorenzo Zanetti (PATA Racing Team) Ducati 1098R 39'13.346
14. Hiroshi Aoyama (Honda World Superbike Team) Honda CBR1000RR 39'21.212
15. Norino Brignola (Grillini Progea Superbike Team) BMW S1000 RR 38'30.959
RT. Leon Haslam (BMW Motorrad Motorsport) BMW S1000 RR 25'10.160
RT. Michel Fabrizio (BMW Motorrad Italia GoldBet) BMW S1000 RR 13'29.654
RT. Marco Melandri (BMW Motorrad Motorsport) BMW S1000 RR 8'23.176
RT. Loris Baz (Kawasaki Racing Team) Kawasaki ZX-10R 8'27.831