Glentoran emerged on top after a seven-goal thriller at Ballymena to move into fourth position in the Premiership.
Alan Teggart fired in the opener after 23 minutes but Jordan Stewart rifled into the bottom corner on 38 minutes.
Jim O'Hanlon tapped the ball under Stuart Addis on 49 and then Marcus Kane curled in a super 25-yard effort on 52.
Unmarked substitute Gary Liggett headed in after 65, Stewart tucked the ball home in the 67th minute and then Teggart pulled one back in added time.
The victory sees Glentoran extend their unbeaten league run to five matches.
Teggart gave Ballymena the lead by powering in a shot at the near post after David Cushley dummied and provided the assist.
The Sky Blues enjoyed the better of the early stages and Tony Kane had a shot saved by Elliott Morris, Allan Jenkins was denied by the visiting keeper and the United skipper also hit the woodwork.
The livewire Stewart seized on a loose ball before finding the net for the equaliser.
Marcus Kane flicked on a free-kick for O'Hanlon to give his side the lead and then Kane dispatched his drive beyond Addis and into the corner of the net.
Teggart provided the cross for Liggett's goal and Stewart outpaced the defence and passed into the net after latching onto a long ball from Jimmy Callacher.
Teggart's late goal proved too late for the hosts, who stay 10th in the league standings.
Meanwhile, Glens winger Stewart has signed a two-and-a-half year contract extension with the east Belfast club.