Ballymena remain level on points with league leaders Portadown thanks to a 2-1 away win over derby rivals Coleraine.
Bansiders striker Gary Browne was denied by Aaron Stewart's goal-line clearance before Gary Thompson slotted in to put the Sky Blues ahead.
Neil McCafferty hit the United woodwork from a free-kick before Browne rolled home a deserved 62nd minute equaliser.
Substitute Michael Ruddy won it 15 minutes later with a close-range header from David Cushley's corner.
Browne was a constant threat for Coleraine and an initial shot was blocked by keeper Dwayne Nelson before the perfectly placed Stewart kept out his second attempt.
The Bannsiders dominated the early stages but United went ahead on 21 minutes when Neal Gawley sent in a corner and Thompson pounced to net in a goalmouth scramble.
Coleraine midfielder Ruairi Harkin looped an early header wide and rifled over before the break while Johnny Taylor glanced wide for the Sky Blues.
McCafferty struck a post with his free-kick early in the second half and it required a goal-line clearance to prevent the ball going in.
Browne saw an effort cleared off the line before he supplied a cool finish into the corner of the United net.
Ruddy was brought on just seconds before he headed in the decisive goal for Glenn Ferguson's team.
"The manager told us to attack them, which we found it tough to do and maybe Coleraine were unlucky," said goalscorer Thompson.
"We're on a high - it might not have been pretty but we got the three points."