Whilst Coleraine had the better of the early stages of the game, it was Bangor who went ahead on 17 minutes.
The Seasiders won a free-kick that was recycled back across goal by Mark Haughey and nodded home by Jay Boyd.
Coleraine were punished again just before the break as Ben Arthurs sprang the offside trap and, despite a heavy touch, he rolled it between the legs of the onrushing Aidan Harris to double the Seasiders’ lead.
However, Lee Feeney’s side were reduced to 10-men just after the break when Harry Lynch picked up a cheap second yellow for a foul on Zane Okoro.
The American loanee then halved the deficit a few minutes later for the Bannsiders when he finished off a loose ball in the box after a stunning save from Deane to deny Declan McManus.
As expected, the visitors laid siege to the Bangor goal and had the ball in the net again, but Matthew Shevlin was flagged for offside.
Bangor were camped in their own half and Shevlin came close to nodding into an empty net late on but for a heroic clearance off the line from Stephen McGuinness while Okoro rippled the side netting.