Defender Ramos was dismissed in the 26th minute, and 11 minutes later Gareth Bale gave Madrid the lead with a fine free-kick, only for the advantage to be almost instantly wiped out by Umut Bulut.
Alvaro Arbeloa and Angel Di Maria netted in the first 20 minutes of the second half, and Isco added a fourth goal for the hosts late on.
"We played very well in the second half whilst a man short. We played with courage and character," said Real coach Carlo Ancelotti.
"Playing with ten is not easy and they all worked well. The match became more complicated following Sergio’s red card and I expect to see him back for the round of 16."
He also highlighted the team’s form: "We’re on a good run, we are scoring lots of goals and playing well. We need to keep the momentum going. I'm happy right now."
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