Manawatu are guaranteed one representative in the Western Alliance grand final on July 30.
The Kia Ora Warriors will host the Feilding Falcons in one semifinal clash next weekend, while Marist host Waitara in the other knockout game.
Feilding might be the defending champions, but they will go into their semi on the back of a 44-24 loss to Waitara on Saturday.
"We got a bit of a lesson," Falcons coach Mike Graham said.
"They just played really well. I know they got a couple of key people back."
Graham said it had been challenging in the back half of the season because of defaults and the bye, meaning his side had not played a lot, while training had also been disrupted because of poor weather.
Kia Ora had the bye during the weekend and the Dannevirke Tigers and Linton Cobras did not play because neither side was able to field a team.
Marist Dragons beat Western Suburbs, 48-6, to warm up for their semifinal, while Normanby-Okaiawa upset the Hawera Hawks.
Weekend scores: Waitara Bears 44 Feilding Falcons 24, Marist Dragons 48 Western Suburbs Tigers 6, Normanby beat Hawera. Linton Cobras and Dannevirke Tigers did not play, Kia Ora Warriors had the bye.
- © Fairfax NZ News