Juventus, inspired by two-goal Alessandro Del Piero, chalked up their first win at Real Madrid since 1962 by beating the Spaniards 2-0 on Wednesday to qualify for the last 16 of the Champions League.
The 33-year-old Italy striker received a standing ovation from the Bernabeu crowd when he was substituted in injury time after an effervescent performance hailed by coach Claudio Ranieri.
Wednesday night's results
AaB 2 Villarreal 2
Arsenal 0 Fenerbahce 0
BATE 0 Zenit 2
Celtic 1 Man Utd 1
Dynamo Kiev 1 FC Porto 2
Fiorentina 1 Bayern 1
Lyon 2 S Bucharest 0
Real Madrid 0 Juventus 2
"When you have a great player who is performing superbly and giving his all for the team the colour of his shirt does not matter," Ranieri told a news conference.
"They applaud because they are applauding football, they are applauding a thing of beauty."
Defeat left nine-times European champions Real in a precarious position in Group H, needing to avoid slip-ups in their final two matches against BATE Borisov and Zenit St Petersburg.
BATE were beaten 2-0 by visiting Zenit on Wednesday.
Real had the lion's share of possession but created few opportunities after Del Piero fired Juve into an early lead when he drilled in a low left-foot shot from 18 metres.
Spain defender Sergio Ramos spurned Real's best chance midway through the second half and Del Piero made it 2-0 with a superb free kick that left goalkeeper Iker Casillas watching helplessly.
"I am extremely happy," Del Piero said. "We won, we have qualified, I scored.
"I am proud of the applause I received at the Bernabeu, an incredible stadium and an extremely important one. You live for these kinds of emotions."
Holders Manchester United, former winners Bayern Munich and Ligue 1 champions Olympique Lyon moved a step closer to the last 16 but Arsenal still have plenty of work to do after a 0-0 home draw with Fenerbahce.
United drew 1-1 at Celtic after a late header from Ryan Giggs cancelled out Scott McDonald's early opener, the Australian striker beating goalkeeper Ben Foster with a delightful lob from the edge of the penalty box.
"In the second half we kept our perseverance and deserved the point but with minutes to go you obviously think you are going to lose," United manager Alex Ferguson said.
"That's football and you keep thinking it's never going to be your night."
The result left the English and European champions top of Group E level on eight points with Villarreal, who drew 2-2 at AaB Aalborg after the home side twice came from behind to keep a mathematical chance of progressing.
Group F took on a similar look after Bayern drew 1-1 at Fiorentina and Lyon beat Steaua Bucharest 2-0.
Tim Borowski struck in the 78th minute to put Bayern level on eight points with Lyon after Juninho and Anthony Reveillere scored in each half for the winners of seven successive French league titles.
Fiorentina have three points and a slim chance of reaching the last 16 while Steaua, who have one point, can only hope for a UEFA Cup berth available to third-placed teams.
Arsenal failed to break down a stubborn Fenerbahce at the Emirates Stadium but still lead Group G with eight points, two more than Porto following their come-from-behind 2-1 win at Dynamo Kiev.
Dynamo are still in contention on five points.