Southern remain the only unbeaten team after beating Taieri 22-11 in a even contest at Bathgate Park this afternoon.
The turning point came right on halftime when Tei Walden grabbed an intercept and off-loaded to winger Jono Hayes. He booted it up field and regathered thanks to a fortunate bounce and then passed to centre Nathan Cargo, who touched down to complete an 80m try.
Bryce Hosie converted to give the home side a 13-5 lead at the break.
Three second half penalties kept Southern ahead.
In the other premier matches, Harbour smashed Pirates 47-8 at Watson Park, Kaikorai upset Dunedin 22-18 at Kettle Park, Alhambra-Union defeated the winless Green Island 18-76 and University A beat Zingari-Richmond 33-32 in a cliffhanger at the University Oval.