Sir Alex Ferguson was left bemused as to how his Manchester United side only won 1-0 against Liverpool in the FA Cup.
United saw off their arch rivals thanks to a first-half penalty from Ryan Giggs, though they had several chances to extend their lead following the dismissal of Reds skipper Steven Gerrard.
"It is amazing it was only 1-0," observed Ferguson. "But sometimes, when a team is down to 10 men, you get that kind of resilient attitude.
"We should have put it to bed in the second half and it could have been three or four.
"But anything can happen at 1-0. The FA Cup is riddled with it.
"Newcastle were reasonably comfortable against Stevenage, then someone shoots from 25 yards and it goes in off the defender's head. The whole game changes. Fortunately, we didn't do anything stupid that would have caused us embarrassment."