Manchester: Cristiano Ronaldo scored the decisive goal as Real Madrid controversially came from behind to win 2-1 at Manchester United and reach the Champions League quarter-finals. (Agencies)
In a breathless game, Nani forced Sergio Ramos to put through his own goal in the 48th minute to give United a 2-1 aggregate lead in the last 16 tie, only for the Portuguese winger to then be sent off for a foul on Alvaro Arbeloa.
Madrid immediately seized the initiative, equalizing through substitute Luka Modric in the 66th minute and then earning victory through United old boy Ronaldo on his return to Old Trafford.
Madrid manager Jose Mourinho conceded his side had been fortunate to go through, telling ITV: "Independent of the (Nani) decision, the best team lost. We didn't deserve to win, but football is like this."
The Spanish champions can now dream of a 10th European title after reinvigorating their season in recent weeks, but United's defeat meant that Ryan Giggs' 1,000th appearance in senior football ended in disappointment.
United assistant manager Mike Phelan attended the post-game press conference in place of manager Alex Ferguson, who he said had been left "very distraught" by Nani's dismissal.
"To play Real Madrid on such a magnificent occasion, with Ryan Giggs reaching 1,000 games and a massive audience around the world, everyone now will be sitting there wondering what happened," he said. "It was a great performance marred by the wrong decision."
Ferguson had sprung a major surprise by naming Wayne Rooney on the substitutes' bench, but Giggs was included in the starting XI as he became only the third British outfield player to play in 1,000 games.
A wave of applause for Ronaldo rippled around the ground at kick-off and the Madrid number seven unexpectedly found himself in direct opposition to Giggs, who started the match in an unfamiliar role on the right flank.
Manchester: Cristiano Ronaldo scored the decisive goal as Real Madrid controversially came from behind to win 2-1 at Manchester United and reach the Champions League quarter-finals.