All eyes on the weekend for the America's Cup

Team NZ and Britannia during the sixth race of the America's Cup series. Photo: Ricardo Pinto / America's Cup

Britannia have made history at the 37th America's Cup as they chase Team New Zealand in pursuit of the Auld Mug in Barcelona.

Team New Zealand had a 4-0 lead before the first British team to enter the America's Cup Match in 60 years won back-to-back races on Thursday (New Zealand time).

The last time a British team scored points in an America's Cup match was 90 years ago.

With the scoreline at 4-2, the America's Cup is now on a knife-edge.

First to seven race wins (match points) lifts the silverware.

The earliest Team New Zealand can win the America's Cup for a third straight time will be on Sunday morning, New Zealand time.

Racing will resume on Saturday (NZT) with races 7 and 8 of the series - weather permitting - with races 9 and 10 scheduled for Sunday.

If the Auld Mug is not won over the weekend, sailing fans will need to get up early on Monday morning for two more races.

If racing goes down to the wire, the final race of the series is on Tuesday.

What happened on the waters of San Francisco 11 years ago will serve as a reminder to Team New Zealand not to get too comfortable with a big lead in the match.

In 2013, New Zealand had a 6-1 lead over the defenders - the American syndicate, Oracle - before the hosts won eight races in a row.

Back then, it was a best of 17 series, which Oracle won 9-8, rather than a best of 13 as it is this year.

The motivation behind the Americans' comeback came from a few words from skipper Jimmy Spithill.

"I think the question is, imagine if these guys lost from here," he said. "What an upset that would be. They have almost got it in the bag. So that's my motivation. That would be one hell of a story, that would be one hell of a comeback and that's the kind of thing that I'd like to be part of."

Sir Ben Ainslie, skipper of Britannia, was onboard Oracle as a tactician during the revival, having come in as a late replacement for John Kostecki when the boat was struggling.

So he knows what it takes to surge past a New Zealand boat and secure the silverware.

After Britannia's two race wins Ainslie said: "Big day, massive day for the team. We really needed that, and I can't say enough about how everyone across the board responded to being four down - the designers, engineers, shore team all coming together to find those little gains, to up the performance out there on the racecourse and that's what we got today."

Asked what the difference was on Thursday in the performance of Britannia, Ainslie added: "It's just little things, it really is. These boats are so fickle in terms of how you set them up and the techniques of how you sail them.

"Going up against the Kiwis and seeing some areas where we were perhaps a little bit behind - so full credit to the coaching team and the engineers trawling through the data trying to figure out how we can make some of those adjustments."

Team New Zealand and Ineos Britannia during the 37th America's Cup Photo: Ricardo Pinto / America's Cup

Despite the challenger's comeback, Team New Zealand helmsman Peter Burling was looking forward to the remainder of the racing.

"We always knew this was going to be a fight; awesome to have a battle on our hands now."