America's Cup 2021: Fickle wind keeps Emirates Team NZ waiting on matchpoint over Luna Rossa.

Emirates Team NZ will have to sweat on matchpoint overnight, after fickle winds again forced postponement to America's Cup racing off Auckland.

Taking a clear 5-3 advantage into Tuesday's racing, the Kiwis move within one win of retaining the 'Auld Mug' with victory in probably the best contest of the series so far, passing Luna Rossa Prada Pirelli on the penultimate leg for a 30-second win.

But with one hand on the silverware, the home team must keep the champagne on ice, with shifty winds winning the race against time to start a second race before the 6pm deadline. 

With the Course C 'stadium course' in play, winds were forecast at 10-15 knots, but race officials had to scramble, when they came from a slightly different direction, delaying the day's first race by 30 minutes. That was always going to make a second race marginal.

When that wind shifted again and died, officials simply could not react quickly enough.

The Italians held the upper hand for much of the scheduled race nine, winning the drag race to the top gate for the first time by one second, but extending that to nine seconds at halfway.

By the end of the fourth leg, Team NZ had closed back within three seconds and were poised to strike late. They made their move near the top of course, when they tacked to the right and Luna Rossa failed to cover.

The Kiwis caught a puff of wind that quickly carried them to a 100m advantage and 18 seconds at the final turn - they were never likely to lose that much downwind to the finish.

"Pretty tight race, all in all, and one little shift in that last beat really decided it for us," reflects Team NZ helmsman Peter Burling. "Good fun racing, good to be back here on Course C, having a good battle with a really good team and walking away with another win as well.

"We're just trying keep learning and improving as best we can. We're to win yacht races, but we'll keep fighting for as long as it takes."

While Burling's ice-cool demeanour should serve him well over the next 24 hours, the nerves of Kiwis sailing fans will be frayed, especially those who still remember the matchpoint heartache at San Francisco 2013.

Leading 8-1 and needing one more win to lift the trophy off Oracle Team USA, Team NZ could not finish the job and the America's reeled off eight straight wins for one of the greatest comebacks in sporting history.

Of course, Aussie Jimmy Spithill - now helmsman aboard Luna Rossa - was the architect of that turnaround, infamous for his "imagine if these guys lost from here" premonition.

That quote may again return to haunt the Kiwis.

Join us at 4:15pm Wednesday for live updates of the America's Cup series between Team NZ and Luna Rossa