OBM had a great tune-up as they took on Hikurangi.
They picked up a comfortable 45-23 victory over the home side, who will be encouraged by how they went in 2017.
The other semifinal will see Waipu travel out to Hukerenui to take on 2016 finalists Mid Northern.
Waipu will be riding a wave of confidence after being the first side to post a century of points as they whitewashed Otamatea 106-0.
Mid Northern meanwhile finished their regular season on a sour note with a 31-17 loss to a Western Sharks outfit looking to scrape into the top four.
They'll know they're up for a real battle against the impressive Waipu but Mid Northern are a quality side themselves so will be more than up for the contest.
In the last game Mid Western finally broke their duck for the season with a tense 23-22 over Kamo.
It's been a long season for the Maungakaramea-based side but they gave their fans something to cheer about going into their promotion/relegation battle.
Meanwhile, the Bayleys Premier Reserve playoffs look like they'll be every bit as exciting as the Premier competition.
Mid Northern will get to host a double header, much to the delight of their home faithful, as they take on OBM at home.
They may have lost their last game of the regular season 33-31 to Western Sharks, but again have proven to be championship-calibre.
They'll take on OBM in a blockbuster home match. OBM come into the match on the back of a 44-19 win over Hikurangi.
The other semifinal pits top-of-the-table Kamo against Waipu.
Kamo grabbed a dominant 72-0 victory over Mid Western in their final round robin match while Waipu were equally clinical in their 48-17 win over Otamatea.
Hora Hora finished the season fifth after a dominant 67-14 win over Wellsford.
Results
Bayleys Premier:
OBM 45 Hikurangi 23
Hora Hora 27 Wellsford 17
Waipu 106 Otamatea 0
Western Sharks 31 Mid Northern 19
Mid Western 23 Kamo 22
Bayleys Premier Reserves:
OBM 44 Hikurangi 19
Hora Hora 67 Wellsford 14
Waipu 48 Otamatea 17
Western Sharks 33 Mid Northern 31
Kamo 72 Mid Western 0
