Down 5-1 in the series, the British face a do-or-die mission today, needing to win at least one race to stay alive.
Anything less and they will be eliminated in the first to seven regatta, with Luna Rossa progressing to the America's Cup match.
While we won't see the heavy breeze that the British crave – with Britannia geared for performing when the wind gets up – it should at least be stronger than Saturday.
Regatta director Iain Murray is expecting between 10-12 knots for the start of the first race at 4:15pm and said it could lift to between 13-14 knots for the second race.
Course A, off the East Coast Bays of Auckland, will be used today.
If the British can extend the contest until Monday there could be more marginal gains, with Murray predicting at least 15 knots of breeze tomorrow.
Murray also revealed that Ineos had lodged a complaint of non-compliance against Luna Rossa last night, over their jib trimming procedure.
Essentially a protest by any other name, the complaint was dismissed by the regatta jury.
Ineos Team UK has port entry for race one, with Luna Rossa first into the start box for the second race of the day.
After a week of storms ashore Ineos Team UK won one of two races sailed in a shifting breeze Saturday to raise the faint hint of a comeback in the America's Cup challenger series final against Luna Rossa.
Sunday will see both teams battle on Course A, off the coast of Milford and Takapuna, in winds expected to range between 9 and 14 knots throughout late afternoon.
Luna Rossa not taking lead for granted
"No high fives yet," Luna Rossa co-helmsman Francesco Bruni said after Saturday's first race-victory which saw the team take a 5-0 lead in the series.
It was a comment made with the prescience of a sailor who knows nothing can be taken for granted in the America's Cup. In 2013 Oracle Team USA came from 8-1 down in the Cup match to beat Team New Zealand 9-8 in one of the great comebacks in sport.
All the evidence of Saturday's racing seemed to suggest, and British skipper Sir Ben Ainslie admitted, Luna Rossa is faster than Team UK's Britannia in a straight line in light winds. But the second race of the day showed the advantage held by a leading boat: Team UK was ahead at the first cross for the first first time in the series and, sailed flawlessly, was able to stay there.
"The guys did a great job," Ainslie said. "They're not going to give up these boys, they're going to keep fighting all the way."
Team UK wasn't happy to be racing Saturday in mostly light winds which favored its opponent and its win was more impressive in those circumstances.
"I think, and most people can see, that at 13 knots and above the boats are pretty even," Ainslie said. "But underneath that we struggle.
"They know it, we know it and that's the challenge we're up again."
Luna Rossa, which controls the Prada Cup as the Challenger of Record, had the ability to demand racing resume after a week-long break due to a small community outbreak of Covid-19 in Auckland which pushed the city to alert Level 3, at which racing generally can't take place.
When Auckland moved to alert Level 2 at midnight Wednesday, Luna Rossa was eager to immediately get back on the water. But it was opposed by regatta organizers America's Cup Events Ltd., which only reluctantly accepted a resumption on Saturday.
Luna Rossa and Ineos Team UK in action. Photo / Dean Purcell
In a bitter and angry dispute, ACE accused Luna Rossa of poor sportsmanship and of failing to honor and respect New Zealanders who have funded the event and whose effort in limiting community spread of the coronavirus made it possible.
Luna Rossa insisted that racing was permitted at Level 2 and should go ahead, though Team UK suggested it acted out of self-interest because it knew conditions Saturday would be light.
The first race started in around eight to 10 knots. Ainslie was especially aggressive in the pre-start as Team UK wanted the windward end of the start line and the right hand side of the course. Luna Rossa sought to shut it out and in the tussle both boats were over the line early.
Those penalties canceled each other out but Team UK was contentiously penalized again for encroaching on the exclusion zone around Prada. When the boats crossed for the first time on the first leg, Luna Rossa tacked on Team UK's lee bow but Britannia edged just ahead.
The umpires insisted Team UK discharge its penalty, which meant it gave up its slight lead, and when it did so Luna Rossa took charge of the race and led by increasing margins at every mark.
"We're obviously struggling in terms of straight line performance so we have to push it hard to make something happen," Ainslie said. "I guess we just fouled out (at the start). It must have been pretty close.
"We got the first cross but they were just sailing away from us with extra speed upwind."
Ainslie pushed hard again in the pre-start for the second race and crossed the line just ahead. For the first time, Team UK's race boat Britannia was ahead at the first cross and able to lee bow Luna Rossa.
With Ainslie and tactician Giles Scott calling the shifts, Team UK led around all marks, including by 34 seconds at the fourth gate. Luna Rossa cut that to nine seconds at the final mark but Britannia held on.
"It was a great race," Luna Rossa co-helmsman James Spithill said. "Full credit to Ineos for getting that one.
"It's always one race at a time and you never think about the end result."
The Prada Cup final is a best of 13 series, with the winner moving on to challenge Team New Zealand in the America's Cup match in March. There will be two races per race day of the Prada Cup final. The racing window for each race day will be around 4pm-6pm, with the first race of each day scheduled for 4.15pm.
Feb 21: Race 7 and 8 Feb 22: Race 9 and 10 (if necessary) Feb 23: Race 11 and 12 (if necessary) Feb 24: Race 13 (if necessary)
The Herald will have live updates on nzherald.co.nz/sport while you can listen to live commentary on Gold AM and iHeartRadio.
America's Cup coverage is free-to-air on TVNZ. You can also stream the action live or on-demand on TVNZ.co.nz or on the America's Cup YouTube channel.
Sunday's racing will take place on course A.
Restrictions at alert Level 2
• Racecourses B & C will not be used for racing, to mitigate the chance of large public gatherings on shore, which are in line with Government Level 2 restrictions.
• No public viewing opportunities such as dock out shows or public screening of racing in the race village.
• Including gatherings of no more than 100 people in the America's Cup Race Village or public spectator vantage points around Auckland.
