The striker was dismissed in the second half of Villa's 1-1 draw with United on Saturday after a 50-50 tackle with former Villa team-mate Ashley Young, but is now available to face Swansea on Boxing Day.
Villa, though, have been charged by the Football Association with "failing to ensure that its players conducted themselves in an orderly fashion" during the game and have until 6pm on December 30 to respond.
But manager Paul Lambert was delighted at Agbonlahor's reprieve after he was dismissed - for the first time in his career - by referee Lee Mason.
He said: "It is great for us
I said at the time I didn't think it was a red card and everyone's assumption was the same.
"Ex-referees have come out and said it wasn't.
"So your own common sense told you it wasn't a red card.
"Gabby is playing really well at the minute so we hoped it would be rescinded.
"We are still without a few - Westy (Ashley Westwood), Nathan (Baker), (Philippe) Senderos and (Kieran) Richardson - so we didn't want another one out.
"Not one of your big players."
The red was Villa's second in two games after Richardson was dismissed in their 1-0 defeat at West Brom.
Richardson is still suspended but Villa have Alan Hutton back after a ban for their trip to the Liberty Stadium while Tom Cleverley is also available following his fifth yellow card of the season.
Source : PA