Southern escaped with a dramatic 23-22 win against the winless Alhambra-Union at the North Ground this afternoon.
With five minutes remaining in regulation time, Southern trailed 22-13.
But winger Piliu Tavake scored in the left corner and Jono Hayes nailed the conversion from the sideline and then kicked a penalty two minutes into injury time to seal the win.
Dunedin upset the previously unbeaten Taieri 48-25 at Kettle Park, while at Watson Park Harbour dominated the forward exchanges to grind out a 32-17 win against Kaikorai.
University A thrashed Pirates 73-3 at Hancock Park and Green Island beat Zingari-Richmond 32-26 at Miller Park.