Warrenpoint clinched their second win of the Premiership season as a Stephen Hughes goal meant that Ballymena United's poor recent run continued.
Sub Hughes scored the only goal on 49 minutes after a Stephen McCabe cross.
Ballymena were left to rue missed chances before the winner with Alan Teggart denied by keeper Johnny Parr and Allan Jenkins also heading wide.
Johnny Taylor was then somehow denied by Parr in the 63rd minute while a Shane Dolan chance was also blocked.
After a quiet opening, Ballymena should have taken the lead on 20 minutes as Teggart only had Parr to beat from pointblank range after Jenkins had nodded across the area, but the Warrenpoint goalkeeper spread himself to make a great save.
Jenkins then headed another great chance wide before the break.
Ballymena were made to pay for their missed opportunities as half-time substitute Hughes slotted to the net after McCabe had picked up a wayward defensive clearance.
Taylor had Ballymena's best chance to level on 63 minutes but with the goal gaping he could only divert into Parr's arms from close range.
Former Donegal Celtic striker Dolan had a later chance but his effort was deflected over the crossbar for a corner.
The win prevents Warrenpoint from slipping to bottom place after Ards won against Ballinamallard while the County Down outfit are now only three points between a quartet of clubs which includes Ballymena and Glentoran.