The United States impressed on the first day of the 49er, 49erFX and Nacra 17 Oceania Championships in Auckland.
American pair Andrew Mollerus and Ian Macdiarmid led the first day of the 49er competition at the Royal Akarana Yacht Club with 11 points.
They finished third, sixth and second in the three races that took place.
Fischer Erwain and Clément Pequin of France are behind them on 12 points after winning two races but placing tenth in the third.
In third on 12 points sit Isaac McHardie and William McKenzie of New Zealand following first, fourth and seventh place finishes.
Home favourites and Rio 2016 Olympic champions, Peter Burling and Blair Tuke, enjoyed a consistent day to see themselves in seventh overall and just five points off the lead.
An American duo also lead the 49erFX event, with Stephanie Roble and Maggie Shea triumphing in two races and coming third in the other to gain five points.
They have a significant advantage going into the second day of competition, with Martine Grael and Kahena Kunze of Brazil their nearest opponents on 12 after second, third and seventh place finishes.
Dutch sailors Annemiek Bekkering and Annette Duetz are in third with 14, having managed to come fourth twice and sixth once.
Ben Saxton and Nicola Boniface of Britain dominated in the Nacra 17 class, emerging victorious from all three races.
With a total score of three points, they lead Riley Gibbs and Anna Weis of the US by five points and Sinem Kurtbay and Akseli Keskinen of Finland by seven points.
Races in all three classes continue tomorrow.