Defending champion Wellington Under 19 had been undefeated throughout the one-day section of the tournament, and headed into the three T20 rounds in a good position to defend their title.
But nothing was locked in - and twin T20 losses on Thursday saw the capital cricketers lose their grip on that coveted silverware.
Wellington had entered the day holding a slender one-point advantage over the charging Aucklanders.
Now, Wellington took two hits - Canterbury taking their first win at Wellington's expense in the afternoon game. Meanwhile, Auckland took two wins and was the only team to win both their T20s in the first two of the three short-format rounds.
And that was enough for Auckland to seal the title - even ahead of tomorrow morning's final T20 round.
Auckland ended the day on 21 points overall, holding an unbeatable five-point margin over the becalmed Wellingtonians in second spot.
T20 ROUND ONE
Northern Districts elected to bat on Bert Sutcliffe Oval but their total was no match for CD when openers captain Emma McLeod (46 off 35) and Vaness Taylor (47 off 56) got going to the top of the chase. CD chased down their target with an over to spare.
On Lincoln Green, Wellington suffered its first shock of the day despite also winning the toss and choosing to set a target. Otago's Louisa Kotkamp again showed how dangerous she can be as she collected a tight 3/14 off her four overs, getting the big wickets early. An ubeaten run-a-ball 51* from Isy Parry then made Otago's position a sound one, chasing down their target in just 17.1 overs.
Auckland was asked to bowl first by Canterbury on Lincoln No.3 and despite a fledgling partnership at the top, Canterbury was soon on the back foot against the tough Auckland attack. Rishika Jaswal was again impressive in Lincoln with 2/9 off her four overs of leg-spin. Teammate Leah Watton backed her up with 2/8 off three. Chasing 83 for the win,the match would go down to the wire, however. Ruby Makeham took a fighting 3/11 as the teams took it into the last over, Auckland bringing home a thriller with just one ball to spare - to move to the top of the overall tournament table.
• Central Districts Under 19 130/4 defeated Northern Districts Under 19 126/5 by six wickets
• Otago Under 19 106/3 defeated Wellington Under 19 102/9 by seven wickets
• Auckland Under 19 85/8 defeated Canterbury Under 19 82 by two wickets
T20 ROUND TWO
In the afternoon matches, CD put Auckland in on Lincoln Green as the big penultimate round got underway. Auckland's Kate Iwin continued her fine form all week at Nationals with a pivotal knock of 64 off just 48 balls at first drop in Auckland's total of 156/3. That was always going to be a tough score to top, and CD crumbled in the pressure chase - losing three of their top four batters for no score. Anika Todd finished with standout figures of 2/3 off her two overs or carnage in a big win for Auckland.
Otago opted to bat first on Lincoln No.3 but it wasn't easy going with ND's opening bowler Aria Mischewski in fire: she hauled in 3/17 off her four overs. Chasing 91 for the win, Northern got there in just 15 overs with six wickets in hand, Tash Wakelin having smashed 27 off just 12 balls to get the chase off to a flier.
Wellington was meanwhile heading into a must-win against the only team that had yet to get off the mark at the tournament. But it would be Canterbury's moment at last, on Bert Sutcliffe Oval. Wellington had elected to bat first, opening batter Neha Ramanathan making 41 at better than run-a-ball. But it was the only substantial score of the innings as Canterbury kept fighting and chipping away with the ball. Abby McKissock had broken the opening stand at 15/1 in the fourth over and she came back to take a further three wickets in her last two overs, including two in two balls, to finish with 4/14. Chasing 103 for victory, Canterbury made a great start with the bat, openers Darcy-Rose Prasad (33 off 42) and Sacha Arnold (33 of 42) putting on 70 together for the first wicket. With the bulk of the work one, Canterbury would cruise home for a satisfying egg-breaker with almost two overs to spare, and seven wickets in hand.
• Auckland Under 19 156/3 defeated Central Districts Under 19 96/8 by 60 runs
• Northern Districts Under 19 91/4 beat Otago Under 19 91/4 by six wickets
• Canterbury Under 19 105/3 beat Wellington Under 19 102/8 by seven wickets
