Buller will host top of the table Mid Canterbury in Westport and should they finish tied with Wanganui on the table, the 15-11 victory on August 31 will carry them through.
However, Mid Canterbury also need the win to claim top spot on the ladder, given Wairarapa Bush face Thames Valley in Paeroa while North Otago should have a straight forward assignment at home in Oamaru against Horowhenua Kapiti.
There is still a tonne on the line for so many teams after the weekend results.
Mid Canterbury comfortably disposed of Thames Valley 44-11, while South Canterbury had their biggest win of the year over King Country, 56-29.
East Coast were leading Wairarapa Bush in Masterton, but two red cards put paid to their chances and they lost 44-31.
Thames Valley and East Coast still have a chance at earning a Lochore Cup semifinal spot, while Mid Canterbury, Wairarapa Bush and North Otago will hunt a table-topping finish to give themselves a shot at two Meads Cup playoff games at home.
Wanganui is really stuck in the swing position.
After playing West Coast, the outcome will determine if they get an away Meads Cup semifinal, a home Lochore Cup semifinal, or even have to settle for an away Lochore game all based on other results elsewhere.