Real Madrid were held to an entertaining 2-2 draw at Juventus, leaving the Spanish side on the verge of qualification for the Champions League knockout stages.
Juventus dominated in the first period and Arturo Vidal gave the Italian side a deserved half-time lead from the penalty spot after Paul Pogba had been fouled by Raphaël Varane.
Cristiano Ronaldo levelled for Madrid with his 21st goal in 16 matches this season and turned provider minutes later as Gareth Bale put Carlo Ancelotti's side in front. But Madrid's lead lasted only five minutes before Fernando Llorente headed Juventus level.
Madrid thus dropped their first points but remain top of Group B with 10 points, while Juventus slip to bottom spot after Copenhagen beat Galatasaray 1-0.
Antonio Conte's team attacked from the outset and Pogba had an early opportunity but fired wide of the left upright from distance.
Madrid had their first chance in the ninth minute when Ronaldo ran half the length of the pitch and into the area before unleashing a shot which fizzed just past the left post
The visitors again went close moments later when the world's most expensive player, Bale, won a challenge with Martin Cáceres for the ball but his tame effort was comfortably saved by the Juventus goalkeeper, Gianluigi Buffon.
Juventus should have scored in the 16th minute when Pogba's cross was almost turned into his own net by Pepe, but Iker Casillas managed to save at point-blank range. Although he spilled the ball, no one could take advantage and the danger was cleared.
The Italian side went closer around the half-hour mark and Claudio Marchisio seemed certain to score with a header, but Casillas did brilliantly to deflect it past his right post with his leg.
Juventus broke the deadlock when Varane slid into Pogba and the referee, Howard Webb, pointed straight to the spot. Vidal stepped up and fired into the top right corner to send Juventus Stadium into a frenzy.
Ronaldo had a chance to equalise on the stroke of half-time but spooned his effort horribly over the crossbar as he was bumped by Karim Benzema.
It was the Portugal star who levelled seven minutes after the interval, chipping Benzema's through-ball over Buffon for his eighth goal in this season's group stage, matching the record held by Ruud van Nistelrooy, Filippo Inzaghi and Hernán Crespo.
It was end-to-end action in Turin and Marchisio again went agonisingly close with an effort which beat Casillas but was cleared off the line by Pepe.
Madrid, who had lost their last five matches against Juventus in Turin, went in front on the hour. Ronaldo picked out Bale on the far side of the penalty area and the Welshman squeezed a shot between two Juventus players and into the bottom corner.
However, Juventus were back on level terms five minutes later when Llorente headed Cáceres' cross powerfully past Casillas' outstretched hand.