Darren Bent instantly repaid a slice of his £18million price tag with the first-half winner for Villa against Roberto Mancini's side.
Kidd admits that is a blow in his side's chances of claiming top spot, but he is confident that City will respond in the right manner and keep their season on track.
He said: "United are going very well; they are undefeated. I always thought it was United's title to lose many weeks ago.
"But this is only a blip. It is already history and we will put it behind us."