Chasing 133, Union lost only Thomas Anderson (40) before Thomas Shields (52 not out) and Antony Cromwell (33 not out) guided them home in the 25th over.
Albion had been well-placed at 103 for three, but collapsed to 132 all out, losing seven wickets for 29 runs.
Amal Asok (34) and Lyle Aichroth (34) led their batting effort.
Union’s Brad Fleming took four for 31, Blake Martin three for 20, and Liam Mavor two for 29.
The victory ensures the Payne Tempero Cup will remain in Union’s trophy cabinet for the winter.
Oamaru eased past Glenavy on the artificial wicket, finishing with 119 for four in 32 overs after Glenavy was earlier bowled out for 117 in 32 overs .
Lachlan Brookes top-scored with 40, while Quinn Wardle finished 22 not out.
Glenavy’s Rodney van Leeuwen took two for 30.
Hamish McCulloch’s 44 provided the only resistance in Glenavy’s innings.
James Ferris (three for nine), Stephan Grobler (three for 32), Hunter Wardle (two for 25), and Quinn Wardle (two for one) shared the wickets for Oamaru.
At Weston, Valley edged St Kevin’s College by 23 runs in the closest match of the round.
Valley posted 148 in 40 overs. Hunter Growcott (30), Cameron Grubb (29), and Shannon Dunnett (25) were the foundation.
Flynn Sanford (four for 26) and Hamish Fowler (three for 31) were the pick of the St Kevin’s bowlers.
The St Kevin’s chase was anchored by Hawke Cup opener Jack Kelly, who made 43 before his dismissal.
Liam Direen tried to guide his team home, but wickets were falling around him.
He was the last man out, also for 43, as St Kevin’s were bowled out for 125 in 39 overs — giving Valley a 23-run win.
Grubb was the star with the ball for Valley, taking five for 25, while Ben Kay chipped in with three for 35.
— Scott Cameron
