Hearts were dazed and McGeady left a clutch of players in his slipstream as he powered forward and slid the ball through to Fortune, who slotted home Celtic's second to keep up his red-hot recent form.
But with the Warriors looking out of the game, an unexpected piece offortune came their way when Colum Halpenny foolishly threw the ball away to give Wigan a penalty from which Ashton nipped over.