Britain's James Peters and Fynn Sterritt won gold in the 49er at the World Cup Series in Enoshima, Japan.
And their compatriot Elliot Hanson is also assured of victory in the Laser, with a race remaining.
His 43-point lead over New Zealand's Thomas Saunders means he is guaranteed the win in Sunday's medal race.
Victory for Peters and Sterritt, meanwhile, added to their success in last year's World Cup Series final in Santander, Spain.
"We're over the moon," said Sterritt.
"It's been an up-and-down week. Everything seemed to go our way in that race. We found our groove and were comfortable with our set-up.
"We were really calm and know we can win when we're under pressure. We kept it controlled. James did an awesome job with the tricky decisions."