The Kiwis, with 26-year-old Peter Burling at the helm, swept the first four races of the match to erase a one-point deficit and take a 3-0 lead in the first-to-seven points series.
HAMILTON, Bermuda, June 23 Mystery surrounds what next for the America's Cup if New Zealand win sailing's most prestigious prize in Bermuda next week.
Jimmy Spithill, the Oracle Team USA skipper, lost his cool over umpiring decisions that have gone against his team in this Americas Cup.
But in a closely fought second race it was Team USA who emerged the victor by 11 seconds.
The next time the boats came together, Team New Zealand was slightly ahead and on favored starboard tack.
"We're comfortable with where we stand", Mr Dunkley said.
Halfway down the run, the Kiwis picked up a nice vein of wind and made a big gain, passing the Americans who were forced into an extra gybe.
Using leg power allows "cyclor" Blair Tuke to have his hands free to trim the hydrofoils that allow the twin hulls to rise above the water, reducing drag and increasing speed.
Races seven and eight are scheduled for Sunday, with the contest now sure to go at least until Monday.
"I'd just like to offer my personal congratulations to the British youth team for winning the Red Bull Youth America's Cup today". Spithill was 30 when he won it in 2010. We had one in the first race in the Qualifiers against us; they should have got a penalty at the top mark.
An America's Cup win would put New Zealand on the map for wealthy investors and make the country a fashionable place to be for more than $500 million in benefits.
"We were really happy with today's racing but we talked about how we had a lot of things we wanted to improve and today's no different".
"We're looking in all areas, including how we sail the boat and how we set it up", Oracle General Manager Grant Simmer told the team's website.
Reflecting on his team's 2013 collapse on the waters of San Francisco Bay, CEO Grant Dalton says: "I don't think you ever get over that".
"We had a really good understanding of what they were trying to be able to do with their starts and a good strategy to oppose it".
Two former America's Cup winners, John Bertrand of Australia and Bertarelli, have been in Bermuda in recent days and could return to the event if the Kiwis win.
However, ORACLE TEAM USA's new-found speed paid dividends on leg 5/7 as they cut the gap to their rivals and engaged in close-quarter racing. We know we can do a better job, technique wise, and clearly we didnt do that in the first [race].