BALLYMENA 9 CORK CONSTITUTION 18, Eaton Park
Scorers: Ballymena: Pens: David O'Hara 3
Cork Constitution: Tries: Richie Lane, Gareth Murray; Con: Scott Deasy; Pens: Scott Deasy 2
Cork Con place-kicker Scott Deasy slotted over two second half penalties and a conversion to ensure his side's quest for a first AIB Cup title since 2006 remains on track.
Brian Walsh's charges were solid throughout and failed to leak a try, despite strong pressure from Ballymena in the opening half.
The visitors led 5-3 at the interval, after a strong second quarter. Ballymena had the better of the opening stages and talented out-half David O'Hara converted a 17th minute penalty kick for the lead.
The wind-assisted Braidmen owned the ball for long spells before Cork Con eventually launched their first serious attack. Right winger Richie Lane broke through for a well-executed try, seven minutes before half-time.
Freezing conditions ensured a hard pitch and the weather worsened before the interval with heavy rain making it even tougher for the players.
The Leesiders broke through for their second try on the restart, with the visitors camped inside the 22. Prop Gareth Murray bulldozed his way through on a surging run to crash over for a telling try. Deasy's successful conversion made it 12-3.
Five minutes later, the hosts were penalised and Deasy once again did the necessary to push his side into a ten-point lead.
Despite Ballymena losing some lineouts in the second half, they held their own in the scrummaging stakes, with O'Hara adding two penalties in the 52nd and 57th minutes to cut the deficit back to six.
But Cork Con looked the more dangerous outfit with ball in hand and a second penalty from Deasy, with 13 minutes to go, sewed up the result and the visitors' qualification for their third ever AIB Cup final.
* Saturday's AIB Junior Cup semi-final ties - Tullamore v Armagh and Monivea v City of Derry - were postponed due to frozen pitches at Spollanstown and the Castle Grounds.