Locked together at 7-7 with the Blues North, a wonderful chip from outside half Owen Williams saw right wing Bowdy Davies race clear and touch down for a converted try that finally put an end to the Blues North resistance.
The sides had played out a first half without any points before the Ospreys turned up the heat in the opening minutes of the second half.
Fullback Sam Hughes provided a constant threat with his elusive running, but it was No.8 Daniel Baker who broke the deadlock when he muscled his way over for a try, which Williams duly converted.
It appeared as though the Blues would have to settle for a runners up spot once again. However, out of the blue, lock McCauley Cook popped up under the Ospreys’ posts to score a try that Joseph Griffin converted.
With extra time ruled out and, subsequently, the two teams poised to share the trophy, the Ospreys struck to break Blues’ hearts when Williams pushed a kick behind the North defence for Davies to race into and score.
The Blues tried desperately to strike back once again in the final 90 seconds, but when Thomson knocked on at half way, the game was up and the Ospreys were left to celebrate another successful evening’s work.
Blues North: H Thomson; A Webber, A Lewis, S Campbell, O Williams; J Griffin, K Marmion; T Emmanuel, C Williams,O Davies, M Cook, J Barley, D Barry, T Young, O Sheppeard
Replacements: L Smout, J Williams, C Hill, J Gibbon, E SHerlock, J Wills, B Jones
Ospreys: S Hughes; Bowdy Davies, D Howell, A Collins, E Walker; O Williams, R Jones (Capt); R Apsee, R Curtis, D Saines, L Joseph, Ben Davies, T Davies, M Sully, D Baker
Replacements: D Davies, B Barlow, T Habberfield, R Thomas, S Pick, S Treharne, L Evans
