Otago have stunned Waikato to 23-19 to seize the Ranfurly Shield and valuable momentum into the Mitre 10 Cup playoffs.
The southerners had to withstand several nervous moments near the end of their challenge and enjoyed a lucky break, when they were penalised under their own posts, but had the penalty reversed for foul play from Waikato.
They were able to retain possession until the final siren to preserve their slender lead and secure the prized 'Log of Wood'.
Playing with a useful tailwind, Otago made all the early running, scoring three tries in the opening 18 minutes, through wing Mitchell Scott, lock Josh Dickson and flanker Joketani Koroi.
But the home team clawed back two tries before half-time, including a crucial one to wing Tyler Campbell as the siren sounded, bringing them back to within eight points.
Eight minutes after the restart, wing Bailyn Sullivan reduced the deficit to just one point with a converted try.
First-five Josh Ioane kicked a penalty to extend the advantage, before Waikato mounted their last desperate - and ultimately fruitless - challenge for victory.
"It's the old cliche - we had to come and attack, and we did," said Otago captain Michael Collins. "Then we closed down at the end and managed to sneak away with the win.
"I'm so proud, we've got a lot of young guys and they've all stepped up."
Despite the losse, Waikato confirmed their inside running for the Mitre 10 Cup championship, finishing the regular season atop the table and booking a home semi against Northland next week.
Earlier in the day, the Taniwha finished fast, but could not overhaul Bay of Plenty in a 38-35 loss. Northland scored two converted tries in the final three minutes, but had already dug too deep a hole to crawl out of.
Later in the evening, Canterbury snunk into second place on the premiership table with a hard-fought 19-14 victory over Counties Manukau, but must now await the result of Auckland vs North Harbour on Sunday to learn their semi-final opponents next week - either Tasman or Auckland.