Ballymena slumped to a 22-12 defeat – their third straight loss – as Cork Constitution’s Conor Quaid, Shane O'Connor and Richard Lane ran in tries.
Quaid started the ball rolling on 13 minutes when he intercepted a midfield pass to run in at the posts.
Four Dirkie Strydom pushed the home side into a 12-7 lead, but O'Connor was mauled over on 71 minutes.
The winning try came four minutes later when full-back Lane coasted over with Whitworth converting.
