Manchester United boss Louis van Gaal praised his team's spirit after overcoming FA Cup opponents Preston North End at Deepdale.
After a goalless first half, Scott Laird put the Lilywhites ahead only for Ander Herrera, Marouane Fellaini and Wayne Rooney - from a disputed penalty - to win it for United.
"(In the) first half I was reasonably satisfied, we don't give anything away which is always difficult in such games, especially against long balls and the fights between central defenders and (Preston striker Kevin) Davies," Van Gaal told BBC One.
"Second half, the (Preston) goal was a little bit unlucky, it was deviated.
"But then we showed an unbelievable team spirit. We changed the shape and that was the solution I think. We scored fantastic goals, (but) a little bit lucky also I think."
