Leaders Portadown wasted the chance to increase their Premiership advantage to five points as they were beaten by bottom club Warrenpoint at Milltown.
Ciaran O'Connor's two goals put Warrenpoint 2-0 ahead at the break and while Gary Breen pulled a goal back, the home side held on to win.
Portadown missed several chances to equalise after O'Connor had struck Warrenpoint ahead on 24 minutes.
O'Connor superbly headed the second goal on 42 with Breen replying on 65.
Portadown did produce late pressure but failed to create any gilt-edged chances to equalise as Warrenpoint held on to move within three points of 11th-placed Dungannon Swifts.
Warrenpoint started impressively as O'Connor hit the woodwork after only two minutes and Mark Hughes then lofted a looping long-range effort on to the Portadown crossbar.
The home side did take the lead on 22 minutes as O'Connor poked in from close range after a low Stephen Hughes cross.
Portadown did respond by creating a series of chances with Warrenpoint keeper Jonathan Parr brilliantly denying Peter McMahon, recalled striker Gary Twigg and Sean Mackle.
Parr's superb reaction stop to prevent Twigg's 34th-minute close-range effort was then followed by the former Shamrock Rovers striker heading a point-blank chance wide with the goal gaping after the ball had been played back into the area.
At the other end, O'Connor wasted a great chance to double Warrenpoint's lead after a gorgeous Stephen Hughes pass on 37 minutes but the striker made no mistake five minutes later as he brilliantly headed a deep Daniel Hughes cross past David Miskelly.
After the break, Warrenpoint had a strong penalty claim turned down after Stephen Hughes appeared to be clipped in the area.
After Miskelly dived full length to deny O'Connor his hat-trick on the hour, Portadown finally did summon up a response as centre-back Breen headed a Chris Casement corner past Parr on 65.
The Ports did have plenty of possession in the Warrenpoint half in the closing 15 minutes but didn't create an obvious goal-scoring chance.
And after the contest, Ports manager Ronnie McFall said that the bottom club had "totally deserved their win" and dubbed his team's performance as "shocking".
Linfield and Cliftonville will both move ahead of the Ports if they win their games on Saturday.