Peterborough brought FA Cup giant-killers Cardiff crashing back down to earth as they won 2-0 at Ninian Park to dent the Bluebirds' promotion hopes.
Leon McKenzie scored on the stroke of half-time for Posh and Neale Fenn added a second 10 minutes after the break to give Barry Fry's men a deserved victory.
A back injury forced Cardiff centre-half Spencer Prior to be replaced by Rhys Weston in the 38th minute.
And Posh took advantage minutes later when McKenzie beat Neil Alexander to a Tom Williams cross to nod into an empty net.
Then early in the second half, Fenn raced between a hesitant Weston and Scott Young to fire home a second.
Leo Fortune-West and Josh Low were introduced by City boss Alan Cork, but they could not prevent a second successive League loss at Ninian Park.
