 Kyle Neill put the Ports ahead with a first half free-kick |
Glentoran 1-2 PortadownPortadown secured a vital victory at the Oval to extend their lead at the top of the Premier Division table.
Gary Hamilton scored the winning goal to deliver a possible knock-out blow to Glentoran's hopes of retaining the championship crown.
With second-placed Linfield only managing a draw away to Lisburn Distillery, the Ports now possess a commanding five-point lead in the title chase.
Glentoran, meanwhile, now find themselves a massive 14 points off the pace.
Portadown's Kyle Neill scored the only goal of the first with a free-kick which got through the Glentoran wall. The Glens felt it should not have been a free but questions must be asked about their ineffective defensive wall.
The Glens battled back and equalised on 65 minutes when Tim McCann headed in from a Darren Armour cross and they almost took the lead when a Gary Smyth header came off an upright.
But Glentoran, unbeaten at home in the league since January, were stunned when Hamilton fired in his 84th minute winner.