One area the home side did dominate, as they have done all season, was in the lower ranks of the men's matches where Duncan Oakley barely raised a sweat, conceding only two games in both matches.
With Opaki's talisman women's player Katie Alsop unavailable, the visiting pair of Georgia Atkinson and Sophie Fitzgerald went in for the kill and went through the fixture unbeaten to wrest the initiative away from Opaki.
The main benefactor of Masterton/Trinity's upset was Gladstone/Carterton, who battled to a 5-4 victory over Martinborough at Carterton, also played on Friday evening.
The backbone of the home side's victory came from their leading men with Matt Spooner, Kelby Courtney and Alistair McWilliam all going through the fixture unbeaten, registering straight-sets wins respectively.
Bruce Lovell was the sole men's victor for Martinborough, reversing an earlier loss to Steve Hurley.
The women's rubbers were keenly contested, but ultimately dominated by Martinborough. Rhona Lovell and Katherine Jacobs would have been well pleased to go through the evening with an unblemished record, and certainly did their part in keeping the tie alive for the visitors.
Martinborough also weren't helped by a serious calf injury to Andy Darling in the doubles that curtailed his night.
As a result of the two fixtures played over the weekend, Opaki still have what should be an insurmountable lead in the race for the Shirley Corlett Trophy. Gladstone/Carterton are four points behind and there is a chance to overhaul Opaki, though that seems improbable.
Results:-
Masterton/Trinity beat Opaki 6-3 (Masterton/Trinity names first). - Men's singles: Jono Hurley beat Brett Dymond 6-0 6-1; Luke Atkinson beat Stu Wyeth 6-4 6-2; Ben Wilkinson lost to Jon McNab 0-6 6-7; Sam Wilkinson lost to Duncan Oakley 0-6 0-6 . Women's singles: Georgia Atkinson beat Nicola Wall 6-0 6-1; Sophie Fitzgerald beat Charlotte Mossman 6-1 6-1. Men's doubles: Hurley and Atkinson beat Dymond and McNab 6-0 6-0; Wilkinson and Wilkinson lost to Wyeth and Oakley 1-6 1-6. Women's doubles: Atkinson and Fitzgerald beat Wall and Mossman 6-2 6-3.
Gladston/Carterton beat Martinborough 5-4 (Gladstone/Carterton names first). - Men's singles: Matt Spooner beat Andy Darling 6-4 6-2; Kelby Courtney beat Rick Wilkie 6-2 6-0; Alistair McWilliam beat Jamie McMaster 6-1 6-4; Steve Hurley lost to Bruce Lovell 4-6 3-6. Women's singles: Karen Herrick lost to Rhona Lovell 2-6 4-6; Zoe Schofield lost to Katherine Jacobs 6-7 2-6. Men's doubles:Spooner and Hurley beat Darling and Wilkie 5-3 (default); Courtney and McWilliam beat McMaster & Lovell 6-2 6-1. Women's doubles: Herrick and Schofield lost to Lovell and Jacobs 6-3 1-6 6-7.
Competition points: Opaki 51, Gladstone/Carterton 47, Masterton/Trinity 43, Martinborough 35.