Dunedin opened the tournament on home courts with a loss and a win.
A 44-31 loss to Auckland in the morning was followed by a 44-24 win over Central Lakes.
Central Lakes had earlier been beaten 59-23 by Cambridge, while Invercargill battled to a thrilling 48-48 draw with Waitakere.
Early warning signals were sent by North Harbour, who crushed Hutt Valley 63-32, and Tauranga, who thumped Christchurch Black 44-29.