Three-time defending champion Tom Slingsby and Team Australia have missed the podium race for the second straight regatta in New York but leap-frogged Spain into second place in the season's SailGP standings.

The Aussies went 9-1 in Sunday's two fleet races on the Hudson River to finish fourth overall in the New York Sail Grand Prix.

The stars of the weekend though were Peter Burling's New Zealand Black Foils, who sailed a flawless podium race to win and also clinch a spot in SailGP's $US2 million ($A3.0 million), winner-take-all grand final in San Francisco next month.

Burling and his mates took the inside position at the start and kept their 50-foot foiling catamaran ahead of Canada's Phil Robertson and Britain's Giles Scott to win for the fifth time in 12 regattas.

They still need to get through the San Francisco regatta in one piece on July 13 and 14 but will have a spot on the starting line of the three-boat grand final for the second straight year.

"It's been a tough season but to just charge through that and get these wins on the board is something we're super proud of," Burling said before the crew members sprayed each other with champagne.

The Kiwis lead Slingsby's team 93-78 on the season leaderboard, while Spain's Diego Botin is third with 76 points.

Nothing is given in SailGP, where penalty points, a collision or a capsize can drastically affect a team's fate.

Slingsby, an Olympic gold medalist and former America's Cup champion, beat Burlng and Britain's Sir Ben Ainslie in the Season 3 Grand Final in tech baron Larry Ellison's global league. The prize money has doubled to $2 million this season for the winning crew.

"Awesome to get another win on the board. Really tricky conditions, really snakes and ladders, but to get three solid starts today, put together three solid races and end up winning it," Burling said. "I'm pretty proud of the team."