The lead swapped several times in Oamaru, with both teams scoring four tries apiece, and the visitors would have thought they had done enough, leading 31-29 with only a minute to play.
But up stepped Rico Muliaina, who slotted a clutch penalty to steal the win 32-31.
Just an hour up the road in Timaru, South Canterbury continued to show why they are serious contenders in 2026, with a dominant 73-10 win over Buller. Sireli Masi nabbed a hat-trick, while Taine Cordell-Hull was again accurate off the tee, slotting 18 points to take his personal tally to 50 for the season.
Across on the West Coast, the home team came out of the blocks firing against Thames Valley, but the visitors ran in seven second-half tries for a 59-35 win. Quinn Collard contributed 19 points off the boot. The big win nudges Thames Valley into fourth place, courtesy of points difference.
Wairarapa Bush hosted neighbours Horowhenua Kapiti and, despite a strong surge in the second half from the visitors, managed to claim a 46-31 win. Wairarapa Bush's forwards were the stars of the performance, accounting for seven of the team's tries.
Mid Canterbury travelled to Ruatoria to face Ngati Porou East Coast and came away with the spoils, winning 57-17. Sam Pearce, Matia Qiolevu and Jackson Donlan all scored twice in the victory.
Whanganui continued their unbeaten run with a 43-15 win over Poverty Bay at home. Alekesio Vakarorogo scored two tries, while Juan Tantrum added 13 points to the scorecard.
South Canterbury and Whanganui sit atop the Hilux Heartland Championship standings, with both facing tough away assignments in round four against Horowhenua Kapiti and King Country respectively.