Tottenham manager Harry Redknapp bemoaned his side's performance and admitted Spurs, who were beaten by United on penalties in last season's final, had let a golden chance to beat the champions slip through their fingers.
"I am very disappointed. You are never going to get a better opportunity than we did tonight.
"We've been playing so well recently but there was no atmosphere.
"It was played at a lethargic pace; we didn't make a tackle in the first half. It was like a practice match, it just never got going.''
Redknapp did not attend the post-match press conference and sent his assistant Kevin Bond instead, who explained: "He probably does not want to say something he might regret.
"The longer the game went on, the worse we got. They were bad goals from our point of view. From then on we never gave Manchester United any problems at all.
"A one off? We certainly hope so. Up until this point all the lads have been fantastic. Hopefully this is a lesson and something that won't be repeated.''