James So'oialo, a former Wellington rep and Samoan test player, added 19 points with a try and six successful kicks.
North Otago recovered from the loss while also putting a reversal of form on Mid Canterbury, beating them 31-25 in Oamaru.
Taking an 11-point lead into the break, the southern team held off the Cantabrians second half comeback, with first-five Dan Lewis having an excellent match with two tries as part of a 21-point haul.
South Canterbury were back in Timaru after their loss to Buller and left sentimental season favourites King Country still searching for their first win after getting home 42-36 in an 11-try match.
Incumbent New Zealand Heartland XV captain Kieran Coll scored a double for South Canterbury, while winger Dean Church got two for King Country, with the scoreline kept close throughout.
Wairarapa Bush needed to get back in the saddle after the humiliation of the 72-point loss to Wanganui last weekend, and East Coast represented a fair chance to do that, with the Bush winning 36-10 in Masterton.
After his health scare last Saturday, with media reports now coming out suggesting he had been getting over a virus from a few weeks before the Cooks Gardens game, Piri Weepu donned his playing strip, while Wairarapa Bush's other halve in Katia Inia scored one of his team's five tries.
Results, September 2.
North Otago 31 (Dan Lewis 2, Lemi Masoe, Mika Mafi tries; Lewis 4 con, pen) bt Mid Canterbury 25 (Maleli Sau 2, Sam Finau tries; Jarred Percival 2 con, 2 pen). HT: 24-13.
Horowhenua Kapiti 39 (Willie Paia'aua, Trent Reti, Nathan Kendrick, James So'oialo tries; So'oialo 4 con, 2 pen) bt Poverty Bay 5 (Isaia Vuki try). HT: 27-0.
South Canterbury 42 (Kieran Coll 2, Marac Beckham, Miles Medlicott, Nick Strachan, Vatiliai Tora tries; Willie Wright 6 con) bt King Country 36 (Dean Church 2, Reese Macdonald, Alex Thrupp, Stephen Turner tries; Kieron Rollinson pen, 2 con; Macdonald 2 con). HT: 28-26.
Wanganui 21 (Timoci Seruwalu, Kaveni Debenaise tries; Craig Clare 3 pen, con) bt Thames Valley 19 (Aaron Carroll, George Lelenoa, Rory Maloney tries; Jarrod Goodall 2 con). HT: 12-8 Thames Valley.
Wairarapa Bush 36 (Eddie Cranston, Tavita Isaac, Soli Malatai, Chris Raymond, Katia Inia tries; Tim Priest pen, 4 con) bt East Coast 10 (Parekura Lalaga try; Chris Palmer pen, con). HT: 17-0.
Buller 34 (Andrew Stephens, Jeff Lepa, Joshua Tuidriva tries; James Lash 4 pen, drop goal, 2 con) bt West Coast 19 (Steve Soper, Tom Reekie, Brad Tauwhare tries; Reekie 2 con) HT: 16-7.