Player-coach Dominic Rayner singled out Collier and Smith, while being pleased overall considering Wanganui came into the weekend with virtually no preparation for playing on grass.
Their results mirror last year's Chapple Cup, where they won one match from three also on the last day against Wairarapa.
"The first game against Manawatu we bowled really well until the 40th over when Roald Badenhorst [93] took it away from us," said Rayner.
"Yesterday [Saturday] we were 50 runs shot, although the boys batted around Smithy pretty well. We just didn't have enough.
"Horowhenua Kapiti probably got 30 more runs than they should have.
"Today we batted really well.
"We fielded really well over the whole weekend, no dropped catches and good on the ground."
On Saturday, after the early loss of John McIlraith, Collier joined Smith and the pair rotated the strike until the 27th over, when Collier was caught by the substitute fielder.
Smith had slowed his scoring but picked up again when Rayner joined him, smacking a quick 20 in 17 balls before being the first of medium pacer Nick Weaver's four wickets.
Everyone else tried to slog and while Weaver went for a few in his six overs, he grabbed scalps throughout as no other Wanganui batsman made more than six runs.
Marlborough's Fraser McIntosh made a watchful start with 47 off 113 balls, and Wanganui had a sniff as Andy Fitzpatrick (23) and Tim Abrahams (5) fell in quick order to Dominic Lock and Trent Hemi respectively, 54-2.
However, from the 32nd over Josh Poole and Greg Stretch put on an unbeaten 95-run partnership at nearly a run a ball to wrap the match up by the 46th over.
Smith, Collier and Hemi all finished with conservative figures but no one had the firepower to break the key partnerships.
That same bowling attack produced a redeeming effort on Sunday, with Collier picking up the key wickets of Matt Fowler (50) and Dion Sanson (31), while Sam O'Leary eventually trapped Matt Bacon (31) as Horowhenua Kapiti's tail wagged slightly after losing wickets steadily throughout.
Rayner also finished with two scalps from his eight overs.
The coach was pleased Wanganui went out with an aggressive approach as they wrapped up the target with 20 overs to spare to end the match early in the afternoon.
Bryce Grant carried his bat through for an unbeaten 63, joined by McIlraith at the finish with 35 not out after Collier had posted another 50 to finish with 153 runs from his tournament.
Wanganui's first game of the Hawke Cup is against Taranaki in New Plymouth, November 18-19.
Rayner said they should have the services of Mark Fraser, the injured Nick Blundell, and the Collegiate representatives to strengthen their chances in that match.
Results
Day 2: Wanganui 221 (B Smith 100, H Collier 54, D Rayner 20, N Weaver 4-37) lost to Marlborough 224-3 (J Poole 85no, F McIntosh 47, G Stretch 41no) by seven wickets.
Day 3: Horowhenua Kapiti 179 (M Fowler 50, D Sanson 31, M Bacon 31, H Collier 4-28, D Rayner 2-22) lost to Wanganui 182-3 (B Grant 63no, Collier 53, J McIlraith 35no) by seven wickets.