Australia lead after opening day of SailGP in Brazil

Three-time SailGP champions and current championship leaders Australia have finished the first day of racing in South America in first place despite not winning a race.

Australia finished second in race one in Rio de Janeiro, then in eighth, third and third to wrap the opening day atop the leaderboard.

Sweden's Artemis won the first-ever SailGP race in South America but struggled later and sit third in the standings, behind Australia and the US.

Helmed by Australia's Olympic gold medallist and America's Cup winner Nathan Outteridge, Artemis won the opening race in Guanabara Bay, with the Sugarloaf Mountain providing the backdrop.

They then finished second in the next race, but the Swedish newcomers struggled in the second half of the day, finishing sixth and ninth.

"Today was very tricky. It wasn't as windy as we thought it was, and if you could get the boat foiling you were away," Outteridge told Reuters.

"Our first two races were awesome, but then we struggled with the starts in the next two races and then had to battle from there. But overall, a good day."

Spain's Los Gallos, Red Bull Italy and Germany's Deutsche Bank won the other races of the day.

The Rio event will be decided on Monday AEST, when three more fleet races will be held before the top three teams from the weekend face off in the event final, a deciding race that crowns the stage winner.

The Brazilian boat, helmed by twice Olympic sailing champion Martine Grael, who won one of her gold medals in the same Rio waters in 2016, had a tough home debut, sitting out the first two races due to a telemetry issue before finishing the day in 10th place among 12 competing teams.

Last year, SailGP cancelled the Rio event scheduled for May after identifying a defect in select wingsails in the F50 fleet. The issue emerged after the Australian boat's wing collapsed in San Francisco, prompting further testing and analysis.