Both the Tanner and Tauranga Cups came down to the last race at the Kohimarama Yacht Club with the top three competitors in both events separated by only one point.
Nathan Vince won the Tanner Cup for Auckland in a breakthrough performance, finishing one point ahead of Canterbury's David Buchanan and Bay of Plenty's Max Scott.
Seb Menzies then pipped the field in the Tauranga Cup, taking the title on coutback from Buchanan with Vince one point behind in third. Vince went into the final race with a one-point lead but narrowly missed out on the double.
The Tanner Cup is one of the most prestigious in New Zealand junior yachting, with previous winners including Chris Dickson, Russell Coutts, Dean Barker and Jo Aleh. The Tauranga Cup is then usually sailed at the same time and doubles as the P-Class national championships.
Menzies arrived just in time for the Tauranga Cup after competing at the 420 world championships in Freemantle, so was battling jetlag and tiredness as well as the mixed of conditions from light breezes to stronger winds.
The 13-year-old is one of the most promising young sailors in the country, last year winning the Aon Emerging Talent at the Volvo Yachting Excellence Awards, and held his nerve in the final race.
Buchanan tried to put a cover on Menzies in the final race with Vince further back but couldn't put another boat in between the pair to take the title.
"It was pretty nerve-racking that final race," Menzies said. "It's pretty significant for me because the P-Class is such a prestigious boat in this country and lots of people who have won the Tauranga Cup have gone on to do well in sailing.
"I'm pretty tired now, but elated."
The big fleets showed the P-Class is still in good health and a feature of the event was a dinner held during the regatta when past winners of the Tanner Cup spoke, including Jimmy Gilpin (1951-53), the only three-time winner, Roy Granic (1964), Murray Thom (1970), Chris Dickson (1977) Jon Bilger (1984-85) and Robbie McCutheon (2016).
One of Dickson's statements was that, 'if you can sail a P-Class, you can sail anything'."
Vince and Menzies will hope that's the case.
Tanner Cup (23 boats)
1st: Nathan Vince (AKL) 3 1 (5) 5 2 1 - 12 points
2nd: David Buchanan (CAN) 2 2 6 2 1 (9) - 13 pts
3rd: Max Scott (BOP) 1 (4) 3 3 3 3 - 13 pts
Tauranga Cup (39 boats)
1st: Seb Menzies (MBSC) 2 (9) 5 2 1 (40 OCS) 1 7 4 3 - 25 pts
3rd: David Buchanan (CBYC) (21) (17) 8 1 5 3 2 2 2 2 - 25 pts
3rd: Nathan Vince (KYC) 1 2 (40 RET) 5 3 1 6 (23) 3 5 - 26 pts