The competition was given an overdue shot in the arm last night when two of the game's heavyweights, with 16 European Cups between them, fought out a thriller at the Bernabéu, Milan coming from behind to edge an ill-tempered yet dramatic clash 3-2 and leapfrog Real Madrid to go top of Group C.
Madrid went ahead in the first half through Raúl, the scourge of European defenders, who equalled Gerd Muller's 32-year-old record of 66 goals in European competition. But two second-half strikes inside four minutes from Andrea Pirlo, with a spectacular long-range effort, and Pato, turned the game.
Royston Drenthe then pulled Madrid level but Pato's exquisite volley two minutes from the end settled it in the Italians' favour. Raúl's night was soured further when he was shown a yellow card after a shoving match involving several players.
"I'm very happy," said Milan's Brazilian coach Leonardo, who has been under fire with Milan languishing in eighth in Serie A. "It gives us a lot of strength winning here. Even after they tied we never thought about losing. I saw always a chance to win. It was an incredible victory."
Madrid coach Manuel Pellegrini countered: "Until they tied it 1-1 we played a good game, we were in control. We then got disorganised and Milan took advantage to win the game."
There were more pyrotechnics at the Stade Chaban-Delmas in Bordeaux, where Bayern Munich's hopes of qualifying from Group A suffered with a 2-1 defeat, the Germans finishing the game with nine men.
Michael Ciani deflected Holger Badstuber's corner into his own net to put Bayern ahead but the tide turned with Ciani's face-saving equaliser and the dismissal of Thomas Muller. Marc Planus scored a second for Bordeaux before half-time and the French went on to have two penalties saved by Bayern keeper Hans-Jorg Butt, the second of which followed a red card for Daniel Van Buyten.
"It's a strange feeling, because we prepared this game very well and we played very bad tonight," Bayern coach Louis van Gaal said. "Our first half was awful."
Giorgio Chiellini's header was enough to give Juventus a 1-0 win against 10-man Maccabi Haifa in Turin. The Italians lie second in Group A behind Bordeaux. The Israeli champions, who faded after a bright beginning and saw the second-half dismissal of Tiago Dutra, have yet to score in the competition.
Besiktas picked up their first point in Group B, Manchester United's section, as the Turkish champions produced a spirited performance to earn a goalless draw at Wolfsburg.
Former Manchester United defender Gabriel Heinze's second-half volley gave Marseilles a win at the third time of asking away to FC Zurich to move back into qualifying contention in Group C.
Jesualdo Ferreira celebrated his 100th win in charge of Porto as Hulk inspired a 2-1 victory over Apoel Nicosia in Group D, leaving the Portuguese champions second behind Chelsea.