Real Madrid star Cristiano Ronaldo felt his side contributed to their own problems against Galatasaray and hopes they will learn from the experience for future matches.
Madrid looked to be cruising through to the semi-finals of the Champions League after Ronaldo's early goal put them 1-0 up at the Ali Sami Yen stadium and 4-0 up on aggregate against their Turkish opponents.
However, Jose Mourinho's men ended up having to weather a second-half storm as Gala struck three times in 15 minutes through Emmanuel Eboue, Wesley Sneijder and Didier Drogba to leave the outcome of the tie in some doubt.
Gala continued to press in the final quarter of an hour but could not find another breakthrough and Ronaldo settled the contest with his second goal in stoppage time, making it 5-3 on aggregate.
Ronaldo, whose side lost Alvaro Arbeloa to a red card late on, believes Madrid should never have allowed things to get as close as they did.
He said: "It was our own fault things became complicated. In football you cannot give anything away and you need to play for 90 minutes.
"What happened here cannot be repeated in the future."
The Portugal international added: "We're happy to have gone through. We've fulfilled the objective and now we wait and see who we're drawn against."
His team-mate Pepe added on Madrid's official website: "The team fought hard and made a big effort.
"We are very happy to get through the tie. In the first half we started very well. It's true that we dropped the intensity a little in the second half and we weren't as good, but we improved at the end.
"The most important thing is that we have got through to the next round."