America's Cup 2021: INEOS Team UK continue to defy expectations, while NYYC American Magic vanish

America's Cup challenger form has been tipped on its head, with fickle winds off Auckland leaving favourites NYYC American Magic becalmed on the competition table.

While INEOS Team UK and Sir Ben Ainslie continued their stunning turnaround from pre-Christmas disaster, Kiwi helmsman Dean Barker was again unable to navigate the vagaries of his Waitematā Harbour homeground, slumping to his second and third losses of the Prada Cup.

After defeating America's Cup holders Emirates Team NZ during last month's world series, the Americans were installed at shortest odds to challenge for the 'Auld Mug' in March.

While the sample size is still small - just two days into six weeks of racing and with plenty of water still to pass under the bow - Barker and his team have been shuffled to the back of the field, barely avoiding the ignominy of two walkover defeats to their rivals.

The New York Yacht Club entry failed to finish within five minutes of Italians Luna Rossa Prada Pirelli in their opening contest and were flagged off the course before they could complete the course.

Against Team UK, they barely snuck under that deadline, although that appeared a very soft call - perhaps a sympathy call - from race officials, rather than imposing another 'dnf' (did not finish).

Both races were plagued by light airs that threatened to delay starts and were ultimately shortened to fit inside the 45-minute time limit. Both opponents cleaned Barker out at the start and unable to find enough puff to foil consistently, he struggled to get back into contention.

His brief moment of optimism came against Luna Rossa, when he trailled by more than seven minutes at the top mark, but miraculously made up that ground and took the lead midway through the second downwind leg.

That jubilation lasted only a few minutes, as Patriot fell of its foils again and the Italians rocketed past, leaving their opponents almost a length of the course behind.

With less than an hour to regroup, the Americans quickly found themselves in trouble against Team UK, penalised twice in the start box and almost two minutes behind at the top mark.

Both boats were struggling in the breeze, which kept it close for a while, but the British were able to build a 2km advantage and hold most of that for victory.

Even Ainslie was unsure how his KZ75 Britannia would perform in light winds, but it was more than good enough for an out-of-sorts New York boat.

"That was a pretty tough race, given what's at stake," says Ainslie, after his third win of the regatta.

"I think it was probably toughest on the grinders, who work hard all the time, but today was just that much more intense, trying to keep the boat on the foil and knowing if you came off the foil, that could be the end of the race.

"I'm not sure today was a really accurate read, because it was so puffy and shifty, and it was just about staying in pressure. Just how we stack up against the other teams, I'm not sure, but still a huge improvement from where we were."

Sunday will see Luna Rossa facing a doubleheader against their two rivals, with the ability of matching Team UK's three wins by the end of the day. 

Join us at 3pm Sunday for live updates of America's Cup challenger racing