Every time it seemed South Canterbury would pull away, the Coasters came back, even after picking up another yellow card, although the home team also had a player sin-binned.
A penalty try let the visitors close the gap to 22-21, and although South Canterbury worked back ahead to 32-21, despite returning goal-kicker Sam Briggs having a rare off day, the Coasters scored again through veteran hooker Troy Tauwhare with six minutes left.
Trying desperately for a seven-pointer, West Coast lost possession and South Canterbury reserve back Clarence Moli swooped to run 40 metres for his second try on fulltime.
If the champions had been nervous, then contenders Thames Valley must have been sweating bullets as a last-minute converted try saved them against a resurgent Mid Canterbury – 34-31 in Ashburton.
Wanting a win for skipper Sam McCahon’s 50th game, the Swampfoxes trailed 17-7 at halftime before a back-and-forth second half, with both teams scoring five tries.
Thames Valley had worked their way ahead 29-24 until the home side scored a converted try with four minutes left.
But the visiting forwards saved the day, pushing hard and earning a penalty in Mid Canterbury’s 35m scrum, and then driving over to score from a 5m lineout.
Those two results set up the competition’s next super-clash this weekend, as Thames Valley hosts South Canterbury in Whangamatā.
Third-place Ngāti Porou East Coast continued their run by hanging on to all the trophies in their derby with Poverty Bay, winning 31-11 in Ruatōria.
Defending the competition-wide Bill Osborne Taonga and the inter-union PJ Sayers Cup, the locals outscored their neighbours four tries to one, with first-five Terangi Fraser contributing 11 points off the boot.
After losing their first three games, Horowhenua’s fortnight run of home matches has buoyed them as they followed up their narrow derby win over Wairarapa Bush with a 33-22 victory over winless Buller in Levin.
The home side had a comfortable 21-5 lead at halftime, and although the visitors had a stronger second half, they could not make up enough ground to remain firmly on the bottom of the table.
Just above them is King Country, their upset victory over Steelform Whanganui now a distant memory after their fourth defeat - beaten 35-26 by Wairarapa Bush on the artificial turf in Masterton.
Stung after losing in Levin following a poor start, this time Wairarapa Bush were fast out of the blocks, leading 19-0, before two tries by King Country saw them close the gap to 19-12 by halftime.
The home side scored only one more try in the second half, compared to two from the Waikato country team, but first-five Tipene Haira coolly slotted three penalties, finishing with a 15-point haul to get his team home and moving back up into fifth on the points table.
Results - week five
East Coast bt Poverty Bay 31-11. HT: 14-6
Horowhenua-Kāpiti bt Buller 33-22. HT: 21-5
Thames Valley bt Mid Canterbury 34-31. HT: 17-7 Mid Canterbury
South Canterbury bt West Coast. 39-26. HT: 14-10 West Coast
Wairarapa Bush bt King Country 35-26. HT: 19-12