The Wanganui team, coached by Ace Malo, started with their campaign with a 21-6 loss to Horowhenua-Kapiti Samoa in Levin, but rebounded by beating Manawatu Samoa 52-29 at Spriggens Park.
To fill the gap week between tournament games, they faced Wairarapa Bush Development last weekend at Spriggens Park for a narrow 29-26 loss.
Wanganui were the defending Cup holders, having upset Hawke's Bay Samoa 23-15 in the final at Marton Park last year, but this season's tournament did not have a grand final.
Hawke's Bay Samoa have been dominant, winning the Cup for three of the past four years.