The leaders have swapped and Wanganui are sitting only a point away from a home Meads Cup semifinal after a round-seven weekend when Horowhenua-Kapiti produced one of their union's best days down in Ashburton.
The visitors beat the undefeated Mid Canterbury 47-43 on Saturday in one of the great boilovers, Teegan Minkley scoring four of his team's six tries.
Down 22-8 and then 36-20, Horowhenua-Kapiti would not lie down and came back every time to secure the upset.
By virtue of still getting two bonus points after scoring five tries, two to Eric Duff, Mid Canterbury stay just ahead of Wanganui heading into the final round, although they also have the advantage if the points finish level after winning the head-to-head game at Cooks Gardens in August.
South Canterbury swept to the top of the table after turning on the gas late in their game with North Otago, winning 58-21 in a blowout.
Sione Vea scored two tries for the victors in the derby game in Timaru.
Under those equations, South Canterbury will now travel to Gisborne to face Poverty Bay, while Mid Canterbury are off to Oamaru to play North Otago this Saturday.
It makes the equation difficult for Wanganui, who have the hardest game of the three against Wairarapa-Bush in Masterton, as the home side are also playing for a Meads Cup berth after a comfortable 45-3 win over wooden spooners East Coast.
The home team scored six tries and will fancy their chances against Wanganui this Saturday, although they cannot pass them on the table.
In the other games, King Country dealt West Coast a costly blow in Greymouth, beating them 36-22 to possibly drop the Coasters out of the Lochore Cup playoffs.
Buller stayed in the hunt after a 25-17 win over Thames Valley in Westport, with Setefano Sauqaqa getting two tries, although having lost to West Coast in round robin, Buller could miss out on semifinals if the points are tied after this coming weekend.
On the injury front for Wanganui, flanker Daniel Fitzgerald will be assessed for a rolled ankle, while captain Peter Rowe came through Saturday unscathed with his calf injury.
Results, Week 7
King Country 36 (Iliesa Tavuyara, penalty try, Rob Sherson, Steve Te Moananui, Matt Rix tries; Zayn Tipping pen, 4 con) bt West Coast 22 (Isei Lawaqui 2, Jason Wright tries; Nik Cumming pen, 2 con). HT: 19-8.
Horowhenua-Kapiti 47 (Teegan Minkley 4, Aaron Lahmert, Jack Taulapapa tries; Brandyn Laursen 3 pen, 4 con) bt Mid Canterbury 43 (Eric Duff 2, Nete Caucau, Adam Ross, Tevita Ula, Seta Koroitamana tries; Andrew Letham pen, 5 con). HT: 22-20 Mid Canterbury.
Wairarapa-Bush 45 (Matt Kawana, Andrew Makalio, So'otala Fa'aso'o, Paul Tikomainavalu, Viliami Hala, Tipene Haira tries; Tim Priest 3 pen, 3 con) bt East Coast 5 (Sam Parkes try). HT: 22-5.
South Canterbury 58 (Sione Vea 2, Erenimo Tay, Miles Medlicott, Theo Davidson, Nick Strahan, Jarrad Matthews, Sione Tauelangi tries; Jared Trevathan 2 pen, 4 con; Jason Merrett 2 con) bt North Otago 21 (Aleki Morris, Sam Sturgess, Rob Mafile'o tries; Jason Forrest 3 con). HT 27-14.
Wanganui 55 (Stephen Perofeta 3, Samu Kubunavanua 2, Michael Nabuliwaqa, Viki Tofa tries; Trinity Spooner-Neera 2 pen, 5 con; Stephen Perofeta 2 con) bt Poverty Bay 23 (Leigh Bristowe, Carl Riini, Kerehama Barrett tries; Ethine Reeves 2 pen, con). HT: 24-13.
Buller 25 (Setefano Sauqaqa 4, Logan Mundy tries) bt Thames Valley 17 (Alan McLean, Moss Doran tries; David Harrison 2 con; Jonnie Te Ruki pen).