The 37th America's Cup is set to commence on August 29 with a round robin tournament deciding who will challenge America's Cup defender New Zealand for the trophy in October.

The Barcelona preliminary regatta on Thursday, however, was plain sailing for the defenders as Luna Rossa Prada Pirelli lost control and retired from the race. 

New Zealand, victors of 36th America's Cup which took place on home seas off Auckland in 2021, ran a tight race with their Italian opponents three years on from when the two teams went head-to-head for the title only for Luna Rossa's systems failure eventually handing them an easy opener.  

"It's a very hard start to start the day like this but luckily that's why we have these preliminary events," said Luna Rossa helmsman Francesco Bruni. "It must have been an electrical issue, I'm 99.9 percent sure it was an electrical problem. We had no functions on the boat working for like 20 seconds. It was not ideal, a little bit scary as well when you have zero control of the boat."

The French team Orient Express got off to a poor start as they were defeated by Switzerland's two-time winners Alinghi Red Bull Racing and then again by a rejuvenated Luna Rossa.

"We did too many mistakes and at this level it's not correct -- we gave the start to Alinghi," said Orient Express's helmsman Quentin Delapierre.

Britain's Ineos Britannia lost to NYYC American Magic by 29 seconds with four-time Olympic sailing champion Ben Ainslie admitting than the American's ran "a great race".

"We've got to get the boat back to the shed, think about what went wrong and how we can get some more pace," said  Ainslie after their defeat this week.

The America's Cup is the oldest international competition still operating in any sport having first taken place off of the Isle of Wight in England in 1851. Races are held between two sailing yachts with one being from the yacht club that currently holds the trophy and another that wins a position to challenge for the cup.