Cluj appeal for handball after the ball appears to strike a Galatasary arm but the referee waves play on.
Galatasaray had a slow start but they've been on top since and that goal is their reward.
GOAL! Galatasaray take the lead! Altintop whips in a superb cross and Yilmaz meets it with a supreme backward header to loop the ball over the keeper and into the top corner!
Galatasaray are knocking the ball around well in front of the Cluj box, looking for a way through the home defence.
Cluj have scored four goals in the Champions League, despite having only fired in five shots on target in the competition.
Kapetanos gets behind the Galatasaray defence again but Muslera is quick off his line to save his side once more!
Altintop tries to bring the ball down in the box but that gives the Cluj defence time to nip in and clear.
Colak shows quick feet to dart into the box before laying off to Riera but his cross is cleared.
The game's settled down after that hectic start, with neither side able to keep possession.
Colak whips the free-kick into the box but it's headed away.
Inan wins a free-kick for the visitors midway inside the Cluj half.
It's been a very open start, with neither defence inspiring much confidence!
Galatasaray make their first foray forward and Colak bursts into the box before poking a shot just wide of the left-hand post!
Galatasary keeper Muslera did well there to put Kapetanos off otherwise the hosts would be 1-0 up.
Kapetanos ghosts behind the Galatasaray defence to bring down a lofted through-ball but can only put his shot wide under pressure from keeper Muslera!
Cluj win a free-kick and it's neatly worked down the right wing but Galatasaray win back possession.
This is a huge night for Galatasaray and, judging by Faith Terim's pre-match comments, they'll be going all out for the win.
Kapetanos almost latches on to Godemeche's through-ball but Galatasaray keeper Musiera is quick off his line to collect.
And we're off! Cluj get the game underway...
Right, we're five minutes from the off! The teams are walking out of the tunnel and, once the pre-match pleasantries are out of the way, we'll be underway.
Here's what Galatasaray boss Faith Terim had to say ahead of kick-off: "It is important that we are adventurous and we go for the win. All sorts of things can happen here, but hopefully we will play well and not make it easy for our opponents."
The reverse fixture between these two sides on October 23 finished in a 1-1 draw, with a Nounkeu own goal giving Cluj the lead before Yilmaz struck back for Galatasaray 13 minutes from time.
Galatasaray's European form makes for grim reading going into tonight's clash. The Turkish club have won none of their last six European games (W0, D2, L4).
Cluj have won just two and lost six of their 10 home games in Europe excluding qualifying games but Galatasaray have taken just one point from their last nine Champions League group games away from home.
THE TEAMS ARE IN! CFR CLUJ: Felgueiras, Pinto, Sepsi, Piccolo, Cadu, Camora, Muresan, Godemeche, Alberto, Kapetanos, Sougou /// GALATASARAY: Muslera, Cris, Nounkeu, Eboue, Altntop, Inan, Riera, Kurtulus, Colak, Yilmaz, Bulut
Here's what Paulo Sergio had to say ahead of his first Champions League game in charge of Cluj: "It is very important that we adapt to the conditions of the match and do not just play a particular system. Possession does not matter as it is the scoreline at the end of the match that counts, and we want to win. If the game ends in a draw then neither team will be happy."
Ex-Sporting Clube de Portugal and Hearts boss Paulo Sérgio has been in charge of Romanian champions Cluj since October 30, filling the vacancy left by Ioan Andone.
TEAM NEWS: Rafael Bastos was forced off early during Cluj's victory over Brasov on the weekend, and he is Paulo Sergio's main injury concern. Galatasaray boss Fatih Terim does not have any fresh injury worries. We'll bring you the line-ups as soon as we have them.
You can follow the action from tonight's other Group H match here on Eurosport.
Cluj go into tonight's game second in Group H with four points from their three games so far. Runaway leaders Manchester United top the group with nine points, while Braga are third with three points and Galatasaray are bottom with just a single point.