Larne Grammar fell to a 15-3 defeat at Cambridge House this week.
The hosts were 10-3 to the good at the interval thanks to Sam Millar who scored a try, conversion and a penalty. Larne’s response came courtesy of a Barry McKay penalty.
There wasn’t much between the sides in the second session with both sets of players battling the elements. But the Ballymena side just had the edge and a Kane McBride try sealed the deal for them.
Elsewhere, Belfast High School narrowly got the better of Antrim Grammar with a 17-14 away success.
The match was played in horrendous weather conditions but it was the Jordanstown school who won the day. Tries from Simon White, Tyler Arnold and Matthew Dennison helped secure the victory, with White adding one conversion.
Antrim’s JJ McKee scored their only try of the game, but three successful penalty kick made sure they remained in contention throughout.
Meanwhile, in the Ulster Schools’ 2nd XV Cup, Ballyclare High School defeated Friends’ School, Lisburn, by 22-10.
Carrickfergus Grammar’s Schools’ Cup match against Strabane GS was postponed.