BALLYMENA 20 OLD BELVEDERE 19, Eaton Park
Scorers: Ballymena: Tries: Jamie Smith, David O'Hara; Cons: David O'Hara 2; Pens: David O'Hara 2
Old Belvedere: Tries: Marcus McAllister, Leo Auva'a 2; Cons: Conal Keane 2
Ballymena, who scored tries either side of half-time through Ulster Ravens starlet Jamie Smith and makeshift out-half David O'Hara, deservedly made it through to the last-four.
Old Belvedere launched a commendable late fightback, scoring two converted tries from number 8 Leo Auva'a, but Conal Keane's injury-time conversion was the last kick of the game and Ballymena hung on.
The Braidmen lost 28-21 to Old Belvedere at Anglesea Road last month and they fell behind today when the Dubliners worked their right winger Marcus McAllister over for a 21st minute try.
O'Hara added the conversion and kicked two penalties to give Ballymena a 13-5 half-time lead, with their forwards beginning to force the issue.
John Andrews' charges enjoyed their best spell in the third quarter and O'Hara sliced through Old Belvedere's inconsistent defence to register his side's second seven-pointer.
Both sides were much changed as the coaches tested their respective squad depth and Ballymena were guilty of falling asleep in the final five minutes as two pick and go efforts from the powerful Auva'a resulted in tries.
Full-back Keane converted the second of them, but time was up and 'Belvo were left to contemplate their second one-point defeat in the space of a week - Phil Werahiko's men lost 13-12 to Galwegians in the AIB League last Saturday.
* Two of Saturday's AIB Cup quarter-finals - Cork Constitution v Queen's University and Dolphin v Galwegians - were postponed due to waterlogged pitches. The draw for the AIB Cup semi-finals will be made on RTE's Sportsbag programme on 2FM on Sunday morning.