Ainslie helped Oracle Team USA rally from an 8-1 deficit to beat Team New Zealand in the 2013 America's Cup before starting his own campaign, which has the backing of the Duke and Duchess of Cambridge. The challenger will still need to win seven in order to pry the oldest trophy in global sports away from powerhouse Oracle.
But they could not repeat the feat against Oracle Team USA and with a win against Ben Ainslie's British team the US crew finished top of the qualifier table. This is the first time the defender has sailed with the challengers in the preliminaries.
In the meantime, they will be looking at flying in a team of boat builders and components to make further changes in their quest for speed, Spithill said at a televised briefing.
If they top the round robin standings they'll take a bonus point into the final stage of their title defence. "You just look at the performance numbers we do every day we get quicker and quicker".
Team France (2-6) shape as the most likely of the five challengers to be eliminated ahead of the semi-finals, having suffered losses to Team Japan (3-4) and BAR on Thursday.
"We've made a decision to face Ben because we believe, with the forecast over the coming week, that's our best chance of progressing forward", he said.
Ainslie has had a troubled campaign so far, including a clash which holed his catamaran and almost ended his dream of bringing the cup "home" to Britain. They are very fast and so for us it will be a real battle.
Their chances of earning the right to challenge Oracle Team USA in the America's Cup finale are "likely to depend on whether they can sort out their issues at either end of the wind range", agrees the Daily Telegraph.
Burling was thrilled with the massive win that keeps Team New Zealand hot on the heels of Oracle Team USA at the top of the table.
In lights winds in Bermuda, USA crossed the finish line 32 seconds ahead of Team Japan despite conceding a penalty at the start of the race.
That heavy defeat put more pressure on the clash with France - who had lost to SoftBank Team Japan by nearly six minutes in the day's opening race - but Britain crossed the finish line just ahead of their opponents to avenge Monday's defeat.
"It was a pleasant prestart; we enjoyed that and the first two thirds of the race", Barker said.
"We have put a fair bit of work into our light air set up and it's really pleasing to see we are somewhat on the pace", he added in an understatement.