Colin Nixon celebrates after equalising for Glentoran
Glentoran moved six points clear at the top of the Carling Premiership after a comeback victory at Stangmore Park.
The Swifts took a ninth minute lead when Sean Ward deflected Johnny Topley's shot into his own net.
Dungannon's Johnny Montgomery was red-carded just before the break after an altercation with Colin Nixon.
The visitors took advantage of the extra man as Nixon levelled with a superb diving header before goals from Mattie Burrows and Daryl Fordyce.
Debutant Ryan O'Neill and Shane Coney went close for the Swifts in the first half.
The game changed with Montgomery's dismissal and referee Raymond Crangle also sent Dungannon boss Dixie Robinson from the dugout after he protested against the decision.
Nixon headed into the top corner from Johnny Black's cross on 62 minutes while Johnny Topley almost restored the host's lead when he sent a header wide seven minutes later.
Burrows put Scott Young's side ahead with five minutes left, stabbing in from Nixon's flick-on.
Fordyce continued his impressive start to the season when he cut inside before firing home to seal the points in injury time.
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