Juan Mata's dramatic late goal earned the Blues an unlikely three points in their quest for Champions League football while United failed to score on home soil for the first time in 67 matches.
However, there was an ill-tempered conclusion to the game, with United defender Rafael da Silva shown a straight red card for hacking at the ankles of countryman David Luiz, who appeared to smile while lying on the ground.
The Spaniard refused to discuss the incident saying he did not see what happened and was keen to look forward to Wednesday's encounter.
"I didn't see the incident or replays," Benitez told Sky Sports. "I try to enjoy when we win, it's a situation you can see 20 times on TV, but it won't change anything.
"For us very game is massive now. This one obviously against the champions was tough, but we did really well.
"We have to beat Tottenham next, which will not be easy on Wednesday and we still have Aston Villa and Everton, so we must carry on, concentrate on the next game.
"Today was a difficult game in terms of the intensity and the tempo. You can see that we didn't have the tempo and they didn't have the tempo, but I think that we were in control."