Manchester United boss Sir Alex Ferguson admits they let Arsenal off the hook after their 1-0 first-leg Champions League victory last night.

In addition to John O'Shea's winner, Cristiano Ronaldo rattled the crossbar, while Ryan Giggs had a second-half effort ruled out for offside on his 800th United appearance.

"Arsene will be thinking it has been a good day for him," reflected Ferguson.

"He could have been out of the tie but he is not.

"But before the game I said I didn't want us to concede a goal and we achieved that. The tie is not dead but we have given ourselves a good chance."