A nine-match unbeaten record fell at The Showgrounds as Dungannon Swifts slumped to their first defeat of the new Irish League campaign.
Goals from Allan Jenkins and Shane Dolan gave Ballymena a deserved three points, ending a run which stretched back to February 2007.
And no-one could argue about the result, with Darren Murphy’s side outplayed over the 90 minutes.
It was a scrappy match at times which, despite producing numerous shots at goal, was low on quality and clear-cut chances.
Jenkins scored with the only real opportunity of the first period to give Ballymena a fully deserved half-time lead.
The real action came in a five-minute period around the hour mark.
Dungannon levelled against the run of play via Darren Boyce, who marked his first start for his new club with a first goal.
But the Tyrone side were on level terms for less than a minute, with the impressive Shane Dolan firing Ballymena back in front.
The result should have been sealed four minutes later, but Alan Davidson’s penalty came back off the crossbar.
This defeat sees Dungannon slip off the top of the table, but that was never going to last long.
Instead Murphy will be more aggrieved at the disappointing performance from his side, who seemed to lack belief, particularly in the first period.
The opening goal came from the game’s first corner after 14 minutes.
A left-foot delivery from Allen Teggert was met by Jenkins, unmarked at the back post, and he rose to power home a header.
Goalkeeper Gareth Buchanan pointed accusingly at his defenders, questioning why the midfielder had been left free.
Dungannon had chances but they were mainly efforts from distance.
Ryan Harpur’s free-kick was well struck but comfortably held by former Swifts ‘keeper Dwayne Nelson while James Costello, who was also facing his former club, went close with an effort which flashed narrowly off target.
Their best chance fell to Harpur, whose powerful drive was too hot for Nelson. Boyce was straight on the rebound but was denied by the ‘keeper.
Ballymena could have added a second via Johnny Taylor. He made a darting run to meet a long free-kick but his header was saved by Buchanan.
The visitors continued to probe for an equaliser. Fra Brennan sent a low effort wide while Harpur’s drive drew another save from Nelson.
Overall, however, it was fairly mundane stuff from Dungannon.
A particular disappointment was the lack of action in the Ballymena box, with all of Swifts’ chances in the first period coming from distance.
Ballymena should have doubled their lead at the start of the second half.
First Dolan’s curling effort came back off the bar, then the striker went close with another shot which Buchanan blocked.
And it seemed the home side would pay for those misses when Dungannon grabbed an equaliser.
Mark McCullough conceded a free-kick and Boyce hauled his side level, dispatching a low effort through the wall and into the bottom corner.
But the visiting fans’ celebrations were cut short within 60 seconds as Dolan made up for his earlier misses.
A corner reached Gary Thompson and he flicked the ball on for the striker, who put Ballymena back in front with a close-range volley.
Suddenly it was all going wrong for Dungannon, and they could have been further behind when Teggert was brought down in the area by the ‘keeper.
A penalty was awarded, but Davidson’s kick crashed back off the crossbar.
It was a lifeline for the visitors, but the Ballymena goal was rarely under serious threat on a frustrating afternoon for Dungannon.
BALLYMENA UTD: Nelson, Kane, McCullagh, Taylor, McBride, Thompson, A Davidson, Jenkins, Teggert (Ruddy, 89), Dolan (Liggett, 81), Lowry (Gawley, 46)
Subs not used: Stewart, Surgenor
DGN SWIFTS: Buchanan, McKerr, Grieve, Brennan, McMinn (Fitzpatrick, 81), Harpur, Hutchinson, McCullough, Boyce, Costello (Douglas, 81), C Lavery (Glackin, 58)
Subs not used: S Lavery, Mulgrew
Referee: Raymond Hetherington (Dungannon)