Imperial Trading Otumoetai Eels premiers will host Hamilton City Tigers on Saturday at Mitchell Park for a place in the WaiCoa (Waikato-Coastline) grand final.
The Eels fell 26-28 in an intense semifinal to Taniwharau, who booked a direct spot in the final by outlasting the fast-finishing side that trailed the entire way.
The Eels had their chances, with playmaker Josh Weedon involved in everything in attack and defence, and were left to rue dropped ball close to the Taniwharau line.
The Eels attacked relentlessly down the stretch, but Taniwharau confirmed themselves as title favourites by defending their line in front of their supporters at Davies Park.
Eels hooker Mikaere October was forced from the field by a dangerous tackle that went unpunished, leaving fullback and player of the day Lance Rolleston to thwart a number of promising Taniwharau attacks.
The Eels' focus now turns to the Hamilton City Tigers, who overcame the Ngaruawahia Panthers 14-8 at Rosehill Park.
The Eels' under-15s beat their Whakatane Razorbacks counterparts 30-14 to advance to the finals as favourites.
Powerful props Jared Ngatai and Charlie Tuimauluga showed the way up front, creating space for a back division led well by Shaun Ryan.