America's Cup defenders Oracle Team USA have five days to find an answer, after they fell 3-0 behind challengers Team NZ off Bermuda this morning (NZ time).
Entering the day 1-0 ahead in their first-to-seven format, the Kiwis showed their archrivals a clean pair of heels, totally dominating both races to extend their scoreboard advantage.
After he appeared to have problems foiling in the box, Emirates Team NZ helmsman Peter Burling conceded the inside running to counterpart Jimmy Spithill at the start of the second race, but steamed over the top of them on the run to the first mark and never allowed their rivals a sniff.
"We just missed getting the board down, we had to slow down and get the board in position, then we were ready to go again," reflected trimmer Blair Tuke.
"By that stage, we had wasted a lot of time, so Pete decided to tack over and from there, we were in a compromised position, but we managed to get some dirty air on them and they couldn't accelerate to leeward of us."
A feature of Burling's performance was a consistently higher, more direct path upwind than the Americans. The Team NZ travelled about 600 metres less than their opponents.
By the end of of the third leg, the margin was 43 seconds - it was a minute at the fifth mark, after the second upwind beat, and one minute 12 seconds at the finish.
"That was certainly another good day for us - putting another couple of points on the board is really good," said Tuke.
"We got a couple of good starts, although that last one was pretty unconventional, but the boat is going really fast, and the boys are doing a good job getting it around the track nice and smooth.
"With boat speed and good manoeuvres, it's turning out quite nicely for us."
With four straight wins over the cupholders, Team NZ are now in the driver's seat and need just three more wins, when racing resumes next Sunday.
But anyone who remembers San Francisco four years ago knows Spithill and his mates are more than capable of engineering a comeback from here, as they did from 8-1 down then.
"We've been here before, so it's not over," warned Spithill. "We've got five very important days and we've got to go to work.
"We've got to get faster, that's obvious."
The key to an Oracle revival may be a change in weather conditions, where stronger winds may play into their hands. The Great Sound offered winds of 9-12 knots today, similar to yesterday and right in the sweet spot for Team NZ's configuration.
Oracle chose to use their high speed foils.
Earlier, Team NZ extended their lead over Oracle Team USA with their third straight win in the day's opening race.
After controlling the start, Burling had the nose of his ACC boat ahead around the first mark and extended his lead to 32 seconds, after Spithill misjudged the third gate and needed an extra tack.
Team NZ were 42 seconds up at the fourth mark and Spithill tried to make up ground by initiating a tacking duel, but Burling wouldn't bite and continued to sail smoothly to the finish, eventually finishing 49 seconds clear.
"I thought the boat was going a lot better today," said Spithill afterwards. "We were able to get off the line well and get round that mark just in front, but unfortunately we just didn't pull that gybe off and they were able to roll us out of the gybe."
5.12am Emirates Team NZ beat Oracle Team USA by 49 secs
5.57am Emirates Team NZ beat Oracle Team USA by one minute 12 secs
Team NZ lead 3-0