Emirates Team New Zealand made a flying start in the America's Cup final with two wins over Oracle Team USA which left the Kiwis 1-0 ahead after the first day of racing in Bermuda's Great Sound on Saturday.

The New Zealand team's double victory erased a one-point advantage the U.S. team earned in an earlier regatta and gave them an early lead as they showed superior speed over the defending champions in the opening races.

"We were far from our best today .... we need to sharpen up and that's what we'll focus on tonight, Oracle skipper Jimmy Spithill told a news conference.

The two wins gave New Zealand a psychological boost as the Kiwis try to win the "Auld Mug" back after losing to Oracle in San Francisco in 2013.

"Day one is massive, it’s the most important day, if someone comes out with a speed advantage, psychologically that’s huge for the rest of the series," said Ben Ainslie, skipper of Land Rover BAR at a morning briefing.

The first direct comparison of the 50-foot catamaran's performance has been much anticipated in the first-to-seven competition. Both teams have modified their boats and the two light wind duels showed the Kiwis' pace.