James Hume scored all 13 points as RBAI claimed back-to-back Danske Bank Ulster Schools’ Cups for the first time in 68 years.
Inst became the first team to win the win the Schools Cup an Medallion Shield in consecutive years and all the first school to win all four trophies on offer in the same season.
Inst made the brght start and were camped inside the Campbell 22 from the kick off and were rewarded with a penalty after two minutes which Hume slotted over after an offence at the ruck.
Campbell wasted an opportunity to level the scores when they turned down a kickable penalty to for touch but lost the resulting the lineout.
Campbell levelled the game after 22 minutes when flanker John Crowther landed a penalty from 35 metres after Inst were guilty of hands in the ruck.
Campbell centre Johnny Haldane made a superb break down the wing he put grubber kick in for centre partner Nicolai Koplesky but Inst captain Conor Field was able to get back and carry the ball dead. From resulting five metre lineout Campbell forced a penalty and again opted for the corner but lost the lineout.
Hume ave Inst a 6-3 lead at the break when he landed a penalty with the final kick of the first half.
Field came to Inst's rescue at the start of the second half with a try saving tackle.
Campbell full back Ben Webb made a serring break down the right wing b was stopped short, the ball was moved to the oppositie side of the pitch for winger Justin Savgae but Field was able to bundle him into touch close to the line.
Crowther missed a chance to level the scores on 49 minutes when he pushed a penalty wide.
Inst winger Mark Keane was sin binned on 55 minutes following a high tackle on opposite number Jack Howard.
With the man advanatge Campbell thought they had the einning try when No8 John Barry Glendining barged over from close range following a patient build up by the forwards but it was disallowed for a knock on in the bulid up.
Inst sealed victory with the final play of the game,Campbell were pushing for a score to win the game when scrum half Malcolm Corry thre a loose pass Hume picked up and sprinted under the posts and converted.