Lennon sees positives after Man Utd defeat
Dimitar Berbatov opened the scoring for United in the 34th minute only for Georgios Samaras to level just after the hour from the penalty spot.
Man of the match Berbatov then set up Danny Welbeck for number two before Tom Cleverley sealed the win late-on.
"I was really pleased with them tonight," Celtic boss Neil Lennon said of his squad. "I thought the level of performance was excellent. A lot of positives to come out of the game.
"For 75-80 minutes, our performance was very very good -- against one of the top teams in Europe."