The British boat, skippered by four-time Olympic gold medallist Ainslie, won the first four of the five fleet races, with Tom Slingsby's Australia taking the fifth.

That win, which followed a second place in Saturday's opening fleet race, clinched a spot in the final for the home boat, but it was a disappointingly one-sided decider.

Slingsby and his crew started the day level on points with Japan, skippered by Australian Nathan Outteridge, who notched two thirds on Saturday.

The home boat was hit with a pre-start penalty before the final and Great Britain charged away to register a convincing win.

"It was nice to perform well today to get into the match race, but I'm upset I made an error," Slingsby said.

"If we'd sailed a great race and they beat us, that's fine. But to get that penalty in the pre-start with no wind meant we were a sitting duck and couldn't get it done.

"As a team, our speed, our teamwork and our manoeuvres are all fine, it's just that when the pressure came on at times we made mistakes.

"The Great Britain team sailed unbelievably over the two days."

The bad news for Slingsby and Australia is that Ainslie believes the British boat can perform even better.

"We still have a lot of small things we can improve on," he said. "We will go away ourselves and look at that, but we'll keep racing hard - it's been a magical first event.

"We have a lot of experienced guys. We came together as a good team and it's great to finish as winners.

"Tommy and the Aussies are the home-town favourites. It was great to be up against them in the match race and to come out on top is a brilliant start for us."

Japan finished third overall, followed by Spain, USA, Denmark and France.

The next round of the 2020 SailGP will be held in San Francisco in May.

Australian Associated Press