The Premier League leaders appeared shell-shocked during the first 45 minutes following the injury to their team-mate and needed a spark after the break to haul them back into the match.
But a match that had merely been smouldering then took flame, Gloucester's Qera providing the spark when he crashed over from close range following a break from Robinson.
Wayne Rooney had United's best chance of the first half, but after the break they struggled to break down Leeds with Alex Ferguson bringing on Michael Owen, Antonio Valencia and Ryan Giggs in a desperate attempt to spark his attack.