First-five James Lash continued his points-scoring spree, getting one of his team's six tries and converting the lot, while Josh Tuidriva dotted down twice in the Westport match.
King Country's defeat opened the door for North Otago to move up into the Meads Cup group with a 48-8 win over East Coast up in Ruatoria.
The game was still alive at 8-2 at halftime, but the southerners lifted with five second-half tries, as Shae Tucker grabbed a hat trick and Simon Lilicama got a double.
Wairarapa Bush continue to recover from losing their opening game after beating a luckless Thames Valley 28-18 in Masterton.
The match was tight at 16-10 at halftime, but the Bush executed stronger in the second half to leave the Valley with just a draw on their tally despite having been competitive in every match.
Mid Canterbury also shook off their loss at home to Wairarapa Bush last weekend with an important 42-26 win on the road in Levin against Horowhenua-Kapiti.
While only scoring five tries to four, Mid Canterbury had better accuracy with the boot as Jarred Percival converted the lot and added a penalty.
The win kept them in the middle of the Lochore Cup group with an outside chance of pushing into the top four, while Horowhenua-Kapiti will have some work to do to stay in playoffs contention.
Results
South Canterbury 52 (Junior Faavae 3, Cameron Bayley, Raitube Vasurakuta, Maxx Morris, Will Joines tries; Zac Southen 3 con, Willie Wright 2 con) bt Poverty Bay 28 (Ratu Daurua 2, Dan McIntyre, Murray Hewson tries; Isaia Vuki 2 con). HT: 28-6.
Wanganui 22 (Te Rangatira Waitokia, Lindsay Horrocks, Renato Tikoilosomone tries; Steve Crosbie con, Dan Whale pen) bt King Country 10 (James Hemara try; Zayn Tipping pen, con). HT: 20-0.
Mid Canterbury 42 (Maleli Sau, Phil Watson, Jackson Donlan, Eric Duff, Richard Catherwood tries; Jarred Percival pen, 5 con) bt Horowhenua Kapiti 26 (Rahiri Connor Johnson 2, Scott Cameron, Nathan Kendrick tries; Warwick Lahmert con). HT: 18-0.
Buller 48 (Josh Tuidriva 2, James Lash, Peni Nabainivalu, Craig Moore, Setefano Sauqaqa tries; Lash 6 con) bt West Coast 0. HT: 18-0.
North Otago 48 (Shae Tucker 3, Simon Lilicama 2, Dan Towler tries; Josh Casey 5 con; Tyron Davies con) bt East Coast 8 (Kareti Palmer try; Todd Doolan pen). HT: 8-2.
Wairarapa Bush 28 (Stanley Wright, John Ika, Glen Walters tries; Tim Priest pen, 3 con; Andy Humberston pen) bt Thames Valley 18 (Bryce Cowley, Ben Bonnar tries; Moss Doran 2 con; Jonnie Te Ruki-Chambers pen). HT:16-10.