Reigning Olympic champions from Brazil and New Zealand struck gold as the first winners were crowned today at the Tokyo 2020 sailing test event.
Martine Grael and Kahena Kunze triumphed in the 49erFX for the South American nation at Enoshima Yacht Harbor as Kiwis Peter Burling and Blair Tuke won the 49er title.
Grael and Kunze won a memorable home Olympic gold at Rio 2016 and topped the charts today after a dramatic medal race on the Japanese course.
All three podium positions changed after the end of fleet racing with Grael and Kunze, who won the Pan American Games title in Lima this month, finishing third to climb up from second place.
Britain's Charlotte Dobson and Saskia Tidey had led from the start but they had to settle for bronze after ending sixth.
Norway's Helene Næss & Marie Rønningen rose from fourth to silver after winning the medal race.
"We had really good gains coming back from the right and we did awesome in the downwinds," said Kunze.
"We were always taking a little bit off each leg and on the last one we managed to secure gold.
"Our target was just to be here, to get everything from the race areas and get used to the climate and humidity."
Grael added: "There's still a lot of events ahead [before Tokyo 2020] for the class – two World Championships, one after each other, and then there's the World Cups and other sailing events.
"We'll need to decide which ones to go to.
"But before that, we'll have a month off."
Fellow Rio 2016 winners Burling and Tuke enjoyed a 13-point overnight lead and knew they just had to beat Poland's Lukasz Przybytek and Pawel Kolodzinski to the line to seal victory.
They duly did so with an eighth place finish as their rivals came home ninth.
Dylan Fletcher-Scott and Stuart Bithell were able to clinch silver from the Poles as they finished third.
Przybytek and Kolodzinski had to settle for bronze.
"This is a big one, being the Olympic test event, and definitely something you're trying to perform well at," said Burling.
"This is the only real practice we get at the right time of year with everything as close as we can with what we're trying to do in a year's time.
"It's pleasing to take a solid win here.
"We feel like we're progressing nicely and getting better as we go."
Three other classes concluded today with China winning both RS:X windsurfing events.
Mengfan Gao wrapped up the men's class as Italy's Mattia Camboni won silver and Piotr Myszka of Poland the bronze.
In the women's fleet Yunxiu Liu triumphed after leading all week thanks to a fourth place in the medal race.
Reigning Olympic champion Charline Picon of France came home first to take silver, as Israel's Katy Spychakov took bronze.
In the mixed Nacra 17 class five boats were in with a chance of victory but Italy's leaders Ruggero Tita and Caterina Banti ended fourth and did not relinquish their position.
John Gimson and Anna Burnet of Britain took silver as bronze went to their compatriots Ben Saxton and Nikki Boniface.
Fleet racing also ended in the five remaining classes today before their medal races tomorrow, although Hungary's Zsombor Berecz wrapped up the men's finn event with a day to spare.
He is an unassailable 23 points in front of Dutchman Nicholas Heiner with Britain's reigning Olympic champion Giles Scott now third.
In the men's laser Jesper Stalheim of Sweden leads he way but only seven points splits the top five.
Tom Burton of Australia is second and Hermann Tomasgaard of Norway third.
In the women's laser radial Belgium's Emma Plasschaert leads with Dutch Olympic champion Marit Bouwmeester second and Hungary's Maria Erdi third.
Only nine points separate the top three so another tense medal race is expected.
Camille Lecointre and Aloise Retornaz of France are in pole position in the women's 470 but their lead over Britain's Olympic champion Hannah Mills and her new partner Eilidh McIntyre is just a point.
Mat Belcher and Will Ryan lead the men's 470, boasting a two point lead over Anton Dahlberg and Fredrik Bergström of Sweden.
Tomorrow is the final day of action with the test event running under the Ready Steady Tokyo banner.
Thirteen sets of medallists at the Rio 2016 test event went on to claim glory at the Olympics, while 18 podium positions were replicated from the 2011 test event at London 2012.