Great Britain have charged to the outright lead of the SailGP standings after winning the Sydney event, with hosts Australia forced to settle for third despite a strong run of results.
Australia (63) finished 12 points clear of GB (51) at the top of the standings after the seven fleet races, three of which they won.
But in Sunday's three-boat final on Sydney Harbour, the hosts incurred a penalty after getting too close to Canada In the first few seconds and were never in serious contention.
Canada led through the first half of the final, raced in winds of about 25km/h.
Great Britain edged ahead in the closing stages to win by nine seconds, with Australia another 25 seconds adrift.
"We felt confident in our boat speed and our boat handling and we felt we've had an edge on them (Canada) all weekend," GB driver and 49er Olympic and world championship winner Dylan Fletcher told AAP.
"We just knew that we needed an opportunity, and we grabbed the opportunity we got given and snuck past them."
Australia driver and CEO Tom Slingsby took ownership of the mistake that caused the penalty, but was adamant it didn't cost the home boat the race.
"I don't want the narrative to be that we would have won the event without that penalty, you just can't say that," Slingsby told AAP.
"Hats off to the British, and it was a mistake by me."
The 10 points for the win lifted GB to 27, three clear of second-placed Australia, with 11 of the 14 events of the 24-25 season to go.
Each event so far has had a different winner, with New Zealand triumphing in Dubai, Australia in Auckland and Great Britain in Sydney, but only GB have been on the podium for all three events.
Australia were the only team to finish in the top three in all eight races in Sydney, notching three firsts, one second and four thirds.
"We're sailing unbelievably well as a team, we've got to be really happy," Slingsby said.
In the first race on Sunday, Great Britain got the jump on the fleet and led all the way, with only much-improved New Zealand staying close and Australia coming home third.
New Zealand, languishing in ninth after day one, followed up their second with a dominant win in the second race, ahead of Canada and Australia.
Only three points separated third from sixth going into the final fleet race, with Australia and GB already assured of spots in the final.
Australia won from Switzerland and Germany and Canada finished fourth to complete their second-day resurgence and clinch the third spot in the final, after being seventh at the end of day one.
"Just came out today swinging and attacking and sailing loose and free and had some good starts." Canada driver and Englishman Giles Scott, a former driver of the British team, told AAP.
"It would have been nice to get one over on the British."
The next event is in Los Angeles in March.
