Centre James Beattie crossed for two tries in a man-of-the-match display as Ballymena came from behind to defeat Dolphin by eight points at Eaton Park.
Having lost their way at UCC last week, Ballymena were determined not to lose to Cork opposition for the second week running. But without their Ulster 'A'-tied players, including top scorer Mark Best, the Braidmen had to battle back from a 9-0 interval deficit.
Buoyed by their home win over Galwegians, Dolphin were good value for that nine-point advantage as lynchpin out-half Barry Keeshan converted three first half penalty opportunities. Their dominant form deserved a try but the hosts scrambled well to keep their line intact.
Keeshan was a commanding presence behind Dolphin's workhorse pack, and their combined influence ensured that the visitors dominated possession and territory.
The major consolation for Andy Graham's Ballymena side was the way they defended and had absorbed the pressure, but their failure to seriously challenge the Dolphin defence was a bit of a concern.
The second period began with the Braidmen in a more determined mood, helped by a mistake by Dolphin who made a mess of the kick-off and handed possession to the hosts on halfway.
Three minutes in, a Ballymena scrum in midfield was easily won and out-half Glenn Baillie put in a superb kick to the left corner, forcing Dolphin full-back Cameron O'Shaughnessy to side-foot the ball into touch, giving Ballymena a promising lineout possession.
A good take in the set piece launched a series of attacks and after a controlled period of possession, James Beattie burst into the line and defied all efforts to bring him down, getting across for his score almost on his knees. Baillie obliged with the conversion and at 9-7 down, Ballymena were back in the game.
Another period of pressure by the home pack gave the backs an opportunity to create space and a great offload by Jordan Foster sent Beattie in for his second try of the day, which referee Brian MacNeice awarded after consulting with a touch judge.
Ballymena were now 14-9 ahead but Dolphin showed they were not yet finished when number 8 and captain Ryan Murphy got over for a deserved try following a lineout drive. Keeshan converted to restore their lead at 16-14. Both sides continued to move the ball wide, but entering the closing stages, it was the home side that got the crucial score.
A clever piece of interplay between scrum half John Creighton and Rodger McBurney created space for the full-back and he sliced through the Dolphin defence at pace, sidestepping past O'Shaughnessy and grounding the ball just to the right of the posts, making for an easy conversion by Baillie.
The scoreboard now showed 21-16. Theat meant the win was still within reach for determined Dolphin, but their efforts to break Ballymena down came to nothing, and they became more ragged as frustration set in.
Things got worse for David Corkery's charges when the Braidmen won a penalty in front of the posts in injury-time and Baillie's successful kick opened up that crucial eight-point advantage.
Referee MacNeice allowed for five more minutes of injury-time, but Ballymena held out comfortably and recorded their third win out of four in the opening tranche of Division 1B games, leaving them third in the table.
Referee: Brian MacNeice (IRFU)