Defending champions the US began the best-of-13 series with a one-point advantage after winning the earlier qualifying regatta, which was erased by New Zealand's race-one win.
Australian Spithill's Oracle team now faces an uphill battle to win the 35th edition of the competition, where the trophy is earned by the first team to reach seven points.
"We're under no illusions", helsman Peter Burling, 26, said.
Other than the Kiwis remaining fast in light conditions, there's not much of a conclusion to draw yet.
The Oracle skipper got a taste of his own medicine after going 3-0 down in the America's Cup this morning.
The New Zealanders are well aware that it is possible not to win the America's Cup despite an early advantage, after being 8-1 up in San Francisco four years ago before losing to Oracle.
Still, this isn't the start the powerhouse Oracle squad expected.
Nothing will escape our eyes, I can guarantee you that in these next five days; whether its system-related, whether its appendage-related, sailing technique, strategy were going to look at everything.
"We've got a lot of great boat building resources, we've got design engineering and we've got a very good group up here". But we had our opportunities. "But we also made a lot of mistakes".
A big percentage of our team has been through some pretty tough situations one, the obvious comeback during the last Americas Cup so this is not the first time weve had to bounce back and really respond from a tough situation.
Burling, who has won Olympic gold and silver medals with grinder Blair Tuke, again appeared unflappable.
Glenn Ashby and Team NZ 3-0 up in America's Cup.
But the Americans aren't to be ruled out of proceedings given their tag as favorites to secure a third straight title.
Racing will resume again next Saturday. The American-backed crew benefited from a wind shift sailing upwind on leg five in Race 2 and made up a huge deficit, pulling right behind the Kiwis sailing through the gate mark. The Kiwis' 50-foot catamaran rose onto its hydrofoils and sped off across the turquoise waters of the Great Sound.
"There are so many things we can work on and improve on", he said. "We were far from our best today".
"Clearly we've got to make some steps forward in boat speed but we've shown we can do it", Spithill said.
Race 4 was to follow.
"We've known all along that to win the America's Cup we had to win eight races and so to get two wins on the board already is fantastic".