A thrilling last 20 minutes gave Vagabonds B the Shimmin Wilson Manx Trophy as they beat Southern Nomads 17-13 in the final.
An Al Landels penalty gave Nomads a 3-0 half-time lead.
Rob Keelan and Josh Samuels both got second half tries for Nomads as they raced into a 13-0 lead.
However, Vagas hit back with scores from Steve Gawne, Jo Louw and Jamie Cooke, plus a conversion from Jack Moore, to steal the game.