Elsewhere, Artemis Racing, led by Briton Iain Percy, produced a remarkable turnaround by winning all three races to turn a 3-1 deficit into a 4-3 lead heading into the final day of racing. Sweden's Artemis Racing now lead their semi-final 4-3.
In this photo provided by the America's Cup Event Authority, SoftBank Team Japan and Sweden's Artemis Racing compete during America's Cup challenger semifinals on the Great Sound in Bermuda on Thursday, June 8, 2017.
"That was a tough race and to come back from 3-1 down - the boys really dug deep".
One challenger will emerge to face two-time defending champion Oracle Team USA in the America's Cup match starting June 17.
In only two years the team launched three race boats, built a new base in Bermuda, brought together a team of over 50, and advanced to within two race wins of the Challenger Playoff Finals.
In stark contrast to Tuesday's poor performance, Nathan Outteridge and his team looked assured throughout the race, maintaining a slender lead over the pursuing SoftBank Team Japan. "It's a big family team here", Outteridge said.
"We hit something just after leaving the marina and didn't have time take the boat up".
If Oracle Team USA or Artemis Racing win, a framework has been agreed among five of the teams for taking it through to the next event, once again in the high-octane foiling catamarans which have proved popular with sailors and broadcasters.
"Before Nath went off it was shaping up to be a really close top mark", said Burling, himself an Olympic gold and silver medalist who went head-to-head with Outteridge in the London and Rio Games.
Outteridge said it's much more than a trans-Tasman showdown between skippers.
Despite the loss, Ainslie was pleased with the progress his team demonstrated.
Burling said such mishaps were "part of it", adding: "I felt like even if he (Outteridge) didn't fall off we would have got that gate (course marker) off him".
New Zealand won the first race of the day, but suffered a shocking setback at the start of the second as their yacht pitched nose-first into the water.