Adomah equalised with a penalty in the final seconds of the first half after Jamie Mackie's 18th-minute goal had put Rangers ahead.
Ghana winger Albert Adomah scored twice in Aston Villa come-from-behind 2-1 win at QPR 2-1 on Saturday in the Championship.
And the winger took his goal tally for the season to eight by scoring what turned out to be the winner 13 minutes into the second half.
It clinched Villa's fourth victory in six away matches and condemned QPR to a second successive defeat.
Steve Bruce's side fell behind after failing to deal with Luke Freeman's right-wing corner - Matt Smith's header resulted in a scramble which ended with Mackie scoring from a yard out.