With a compelling current and whipping wind on San Francisco Bay, Italian skipper Max Sirena thought racing twice a day in the America's Cup challenger finals would be "pretty painful" for the new high-performance catamarans. Just finishing one race has proved problematic. Emirates Team New Zealand sailed away with another win because of a mechanical failure to Italy's Luna Rossa, taking a 2-1 lead in the Louis Vuitton Cup finals. Skipper Dean Barker guided his boat underneath at the start and made a slick move inside Luna Rossa on the first turn to go ahead. The Italians started strongly and stayed close until the control arm of their wing broke, forcing another withdrawal in a series beset by big breezes and breakdowns. "I would not be sleeping well if I was the designer of one of these boats," Sirena said. For the third straight day, officials called off the second race due to excessive wind - and bailed out a broken boat. All three wins in the finals have come by withdrawals. The winner of the best-of-13 series will face defending champions Oracle Team USA in the 34th America's Cup starting on September 7. "It's getting massively frustrating," Luna Rossa grinder Giles Scott said. "At the moment, the racing has been almost governed by who can get around the course as opposed to win the races." This summer has been full of setbacks for the regatta. British sailor Andrew "Bart" Simpson died in the capsize of Swedish Team Artemis Racing's first boat during a training run on May 9. Oracle are still fighting off an alleged cheating scandal for illegal modifications to their prototype boats used last year and early this year. And the 72-foot catamarans - so expensive and dangerous that only three challengers entered the competition - are failing more than foiling. "It'd be nice if we can get one race where both boats race all the way till the end," Barker said. The New Zealanders went 5-0 against the Italians in the round-robins, including the opener that Luna Rossa boycotted because of a rules spat - another embarrassment to the regatta. They twice beat the Italians by more than five minutes, and the closest margin was 2:19. The current course is five legs, which is three shorter than the one used during the round-robins. Sirena said he "never thought we could be so close in performance" to Emirates now and is hoping to get the chance for a head-to-head race till the finish. He said part of the problem for the breakdowns in the finals is that the "fragile boats" are still so new and being pressed harder than ever before. "When you're sailing alone around the course, even in 20 knots, you'll really be scared because you can put the boat down," Sirena said. "Then when you have another boat next to you, that scare has gone away because you want to beat the other guy and you push way harder than normally."