Juventus paid for defensive errors, as they were trailing Roberto Mancini’s Galatasaray, winning and eventually held to a 2-2 draw in Turin.
In the other Group B game, Real Madrid thrashed Copenhagen 4-0  and go four points clear at the top.
Carlos Tevez shook off an ankle injury to start with Mirko Vucinic, while Andrea Pirlo returned after he was rested for the Turin Derby. Galatasaray sacked Coach Fatih Terim due to a 6-1 defeat to Real Madrid and a contract dispute, so Roberto Mancini made his debut just two days after signing a three-year contract. Having barely even met the squad, he dropped Burak Yilmaz in favour of lone striker Didier Drogba, ex-Inter man Wesley Sneijder and former Juve flop Felipe Melo. Hamit Altintop and Eray Iscan missed out.
The pressure was on Juventus to win after a surprise 1-1 draw away to FC Copenhagen, but it was a relatively cagey start. Paul Pogba attempted an audacious overhead kick from Arturo Vidal’s cross, but barely made contact with the ball.
Gigi Buffon needed quick reactions and used his foot to deny a Drogba strike at the base of the near post, as the ex-Chelsea man was going to score from the tightest of angles. Bruma also tested Buffon, though this smother was simple.
Vucinic ran on to a wonderful Pirlo ball over the top, but stumbled and then collapsed clutching the back of his leg. The Montenegrin limped off for Fabio Quagliarella, while in the same move Semih Kaya also picked up an injury.
Quagliarella could easily have won a penalty with practically his first touch, as he prodded a Tevez pull-back wide from close range due to a shove in the back by fellow substitute Gokhan Zan.
Tevez and Stephan Lichtsteiner shots were charged down in the box, as the Bianconeri began to pile on the pressure.
However, just as Juve seemed ready to find the breakthrough, it was Galatasaray who opened the scoring. Leonardo Bonucci’s dismal backpass was intercepted by Drogba and Buffon came tearing out, but the Ivorian kept his cool to deposit into an empty net. It was Drogba’s third career goal past Juventus and for the fifth time this season conceded the first goal.
Tevez fought back immediately, his scorching strike on the turn whistling just wide, but Sneijder also volleyed well over from a promising position. Kwadwo Asamoah’s powerful effort was straight at ex-Lazio goalkeeper Fernando Muslera and Quagliarella did the same when redirecting Lichtsteiner’s cross from point-blank range.
Lichtsteiner also picked up a muscular problem on the stroke of half-time, so made way for Mauricio Isla after the break. Vidal and Asamoah fired opportunities off target, then Tevez aimed straight at Muslera after a splendid turn.
Pirlo and a Vidal volley from a corner sailed over the bar, while a crucial tackle stopped Quagliarella going clear on goal.Vidal aimed another long-range strike that scared Muslera and Emmanuel Eboue’s sliding challenge stopped Pogba pulling back from the by-line for Quagliarella.
Antonio Conte had to take a risk and threw on Fernando Llorente for Bonucci. It was his Champions League debut and he almost scored with his first chance, getting between centre-backs to nod an Asamoah cross just over the bar.
Juventus were awarded a pretty soft penalty when Quagliarella made the most of a mistimed Nordin Amrabat challenge, going down easily. Vidal stepped up and blasted a powerful spot-kick under the bar to draw Juventus level. Ex-Inter Coach Mancini smiled ruefully on the touchline when the referee pointed to the spot, but it was an entirely avoidable challenge from his player.
Llorente had the ball in the net, but it didn’t count because Tevez was offside in the build-up. However, moments later Juve did take the lead, as Pirlo whipped in a cross from the right that Quagliarella nodded in from six yards. It was his second goal in as many Champions League games this season.
However, Juve were still celebrating when Galatasaray got back on level terms. There was a visible gap in the Bianconeri defence’s right flank where Umut Bulut had time and space to control a Drogba knockdown and fire past Buffon.
Llorente toe-poked wide when a Tevez effort ricocheted into his path in stoppages.
Juventus 2-2 Galatasaray
Scorers: Drogba 36 (G), Vidal pen 78 (J), Quagliarella 87 (J), Umut Bulut 74 (G)
Juventus: Buffon; Barzagli, Bonucci (Llorente 68), Chiellini; Lichtsteiner (Isla 46), Vidal, Pirlo, Pogba, Asamoah; Vucinic (Quagliarella 26), Tevez
Galatasaray: Muslera; Riera (Amrabat 60), Chedjou, Semih Kaya (Gokhan Zan 25), Eboue; Felipe Melo, Selcuk Inan; Bruma, Sneijder (Umut Bulut 74), Hakan Balta; Drogba
Ref: Kassai (HUN)