Next weekend Northland will face North Harbour in Silverdale at 1pm before facing Auckland West in Dargaville.
The semifinals will take place on October 4 before the finals on October 5 in Tauranga.
Other Northland representative teams weren't able to emulate the Roller Mills team.
Northland's senior B team lost 27-23 to Bay of Plenty while the Northland Colts went down 74-8 to Counties Manukau.
The Northland under-19 side lost to North Harbour 50-10 and the North Zone under-16s lost by a similar margin in going down 47-7 to Auckland East.
Meanwhile, the South Zone under-16s lost 17-10 in a close one to Auckland South.
North Zone under-14 lost to Auckland East 55-5.
Northland 48 (Tawa Holyoake, Connor Guest, Kawai Wihongi, Zac Hamlin, Leighton Hamuera, Rocky Olsen, Max Brunker 2 tries; Mikey Tangimetua 4 cons); Thames Valley 5. HT 19-0.
Run into the finals:
v North Harbour, Silverdale, 1pm, September 20.
v Auckland West, Dargaville, 12pm, September 27.
Semifinals/finals, Tauranga, October 4-5.