Team New Zealand now needs just three more races to win the America's Cup but warns the racing is still very close.
The challengers won both races in the America's Cup series on Friday, giving them six points against Oracle's one. The winning margin in the first race was 47 seconds and in the second race 1 minute 6 seconds.
However, the team's chief operating officer, Kevin Shoebridge, says the New Zealand camp is not over-confident.
"Everyone here is very considered about what they say, and definitely no-one's getting ahead of themselves.
"As you can see it's still very, very close racing and there's still another three races that we need to get old of. And it could be quite a bit of breeze; a different set of conditions again that we havn't dealt with. You never know what can happen on the day."
Team New Zealand needs nine wins on San Francisco Bay to take the trophy from Oracle.
The challengers again proved much faster than Oracle on the up-wind leg.
After a poor start in the first race, Team NZ skipper Dean Barker told TVNZ he wanted to make sure he got away in front, in the second.
The next two races are scheduled for Sunday (New Zealand time).
Oracle earlier changed its tacticians for the two races on Friday, with British Olympic star Ben Ainslie replacing American John Kostecki.
Former America's Cup skipper Chris Dickson earlier said the move by Oracle to replace the tactician would not be a game changer.
He said it was just symbolic more than anything and he was not surprised by the move.
NZ betting closed
The TAB has closed the book on who will win the Cup.
The agency says it now considers it a matter of when, not if, the challengers are victorious, and has instead opened a book called Will Oracle Win Another Race?