MANCHESTER, England (REUTERS) - Former Manchester United hero Cristiano Ronaldo scored the winner as Real Madrid knocked out a Manchester United side controversially reduced to 10 men in the Champions League on Tuesday.

Ronaldo secured a 2-1 win for Real and a 3-2 aggregate success after the match completely changed when United winger Nani was sent off for a clumsy, but not deliberate, high challenge on Real defender Alvaro Arbeloa in the 56th minute.

The red card came as a total surprise and was the start of a terrible 13-minute spell that doomed the home side to defeat as Real, trailing 1-0, struck twice in three minutes through Luka Modric and Ronaldo to seal Real's place in the last eight.

Substitute Modric, only been on the field for seven minutes, lashed in Real's equaliser from 20 metres after 66 minutes and Ronaldo slid in at the far post three minutes later to turn in a cross from Gonzalo Higuain and seal Real's place in the last eight.