The penalty came after Cleveland Taylor was bundled to the ground by Daniel Jones. The on-loan left-back was shown a straight red card for the clumsy challenge. But Neal Eardley lashed home a 30-yard free-kick to level the match late on.
United boss Greg Abbott kept faith in the same side that earned a valuable point away at Leicester last weekend. For large periods of the first half it was, however, Joe Royle's Latics who were playing some lovely free-flowing football.
The Latics should have gone ahead after three minutes when Chris Taylor hit the post with a header. Carlisle came back into the game and Peter Murphy's glancing header went inches past the post from a Ian Morris throw-in. Graham Kavanagh, Joe Anyinsah and Taylor all had chances, but it was Bridges' spot kick just before the break that gave the Cumbrians the lead.
The former £6million man had a glorious chance to double the lead in first-half injury time, but he fell while shooting with just Supple to beat. Carlisle dominated the second half and had a number of chances to extend their lead. Bridges brought a point-blank save from Supple just after the hour mark, Taylor hit the post from a tight angle and another Bridges shot was well blocked.
Super sub Scott Dobie was a stud's length away from finding the net after Taylor crossed from the right, but Eardley's late strike means Carlisle are still deep in a relegation battle. The home side's inability to convert their chances being the reason they could start next season in League Two.