Wanganui had every reason to expect to meet South Canterbury in a repeat of last year’s Meads Cup Mitre 10 Heartland final next week, but Buller produced an upset in Timaru.
The home team could score only one try to Kalavini Leatigaga while Buller, who led 8-6 at half-time, produced two for a 16-6 win.
Wanganui unleashed their firepower to shut Wairarapa Bush’s ambitions down courtesy of a 58-26 win at home.
On the other hand, in the Lochore Cup, defending champion King Country will host North Otago in a repeat of last year’s final.
North Otago upset Mid Canterbury in Ashburton 36-24 while King Country beat Poverty Bay 48-26.
Heartland semi-final results:
South Canterbury 6 (Kalavini Leatigaga try )
Buller 16 (Setefano Sauqaqa, Peni Nabainivalu tries; James Lash 2 con)
Wanganui 58 (Malakai Volau, Michael Nabuliwaqe, Blake Hohaia 2, Ace Malo, Te Rangitira Waitokia, Craig Clare tries; Clare 6 con, pen; Dane Whale con)
Wairarapa Bush 26 (Eddie Cranston 2, Glen Walters, Zac Guildford tries; Andy Humberston con)
King Country 48 (James Hemara 2, John Koko, Anthony Wise, Rob Sherson, Alex Thrupp, Dean Church tries; Zayn Tipping con, 2 pen)
Poverty Bay 26 (Ratu Daurua, Dan McIntyre, Everard Reid tries; Isaia Vuki con)
Mid Canterbury 24 (Jarred Percival, Brendon Rigden (2) tries; Jarred Percival 3 con)
North Otago 36 (Lemi Masoe, Marene Mapusage 2, Matthew Vocea, Robbie Smith tries; Craig Smith 2 con; Tyron Davies pen)