Great Britain's Giles Scott has earned his first SailGP victory, shortly after three-time defending champion Tom Slingsby and Team Australia capsized in a dramatic moment in the rainy, blustery inaugural Canadian Sail Grand Prix Halifax.

Scott, elevated to skipper after Sir Ben Ainslie stepped aside in January, beat France and Denmark in the first all-European podium race in the four seasons of tech billionaire Larry Ellison's global league.

While Scott enjoyed his first Champagne shower as skipper, a frustrated Slingsby said a technical issue led to the capsize of his 50-foot foiling catamaran that might have cost the Aussies a spot in the podium race.

The Aussies were leading the fifth and final fleet race when the Flying Roo suddenly rolled over, with the tip of its wingsail -- adorned with the outline of a yellow kangaroo -- resting in the water. No sailors were injured, but Slingsby said he fell out of the cockpit and was able to hold on, and that strategist Natasha Bryant could have easily fallen.

"It was a pretty dangerous situation how quickly it happened but everyone's safe," said Slingsby, a gold medallist and former America's Cup winner.

"We've got to just be thankful for that and try to get the boat working and we've got two events to try to pull back in."

The Aussies almost capsized in the fourth fleet race, heeling over dangerously before getting the cat under control.

It was just the second time in SailGP history that a team from Down Under wasn't in the podium race.

It was a huge victory for Scott, a two-time Olympic gold medallist who became skipper when Ainslie stepped aside on January 4, mostly to focus on the America's Cup later this year. Ainslie, the most decorated Olympic sailor in history with four golds and a silver, remains CEO and majority owner of the British SailGP team. Scott is on Ainslie's America's Cup team, INEOS Britannia.

Britain reached the podium race for the first time since Ainslie skippered them to consecutive regatta wins in September.

"Buzzing. Absolutely buzzing," Scott said.

"Awesome day. Just feel very fortunate to have an amazing crew to sail with. We nailed it this weekend. Really stoked."

Scott's crew includes strategist Hannah Mills, the most-decorated female Olympic sailor with two golds and a silver.

The British are sixth in the season standings, 13 points out of podium position with two regattas to go before the $2 million, winner-take-all Grand Final among the top three boats on July 14 in San Francisco.

New Zealand, led by reigning two-time America's Cup champion helmsman Peter Burling, continue to lead the season standings. Diego Botin of Spain jumped into second place overall, 11 points behind the Kiwis and one point ahead of the Aussies, who are six points clear of France.

Spain finished fourth, the Kiwis fifth and the Aussies seventh in Halifax.