Riley McDowell crosses the line for Kaikorai. Photo: Gregor Richardson
Kaikorai will meet University in the semifinal next week while Taieri will take on Harbour.
Southern had a chance to make the top four but had to win big. It didn't - losing 27-26 to Alhambra-Union.
In the other games, Taieri beat ZIngari-Richmond 74-19 while Dunedin beat Green Island 36-22.