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SAN FRANCISCO, CA - AUGUST 17: Oracle CEO Larry Ellison waves from a boat before the start of race one of the Louis Vuitton Cup finals on August 17, 2013 in San Francisco, California. Emirates Team New Zealand won race one after Team Luna Rossa Challenge did not finish. The winner of the Louis Vuitton Cup goes on to race against Oracle Team USA in the America's Cup Finals that start on September 7. (Photo by Justin Sullivan/Getty Images)

SAN FRANCISCO -- The America's Cup continued to be dogged by breakdowns of the high-tech catamarans Sunday when Emirates Team New Zealand, leading Italy's Luna Rossa Challenge in the second race of the Louis Vuitton Cup finals, slowed to a stop and withdrew from the race.

The hefty battery pack that controls the electronics on board failed, crippling the hydraulic system operating the rake of the daggerboards and the shape of the 130-foot wing sail.

"I'm devastated. That's one we had in the bank," New Zealand tactician Ray Davies said. "It was just disappointing to have a silly issue like that."

Emirates Team New Zealand crew members make repairs to their damaged catamaran following the first race of their America’s Cup challenger series
Emirates Team New Zealand crew members make repairs to their damaged catamaran following the first race of their America's Cup challenger series final sailing event against Luna Rossa Challenge, of Italy, Saturday, Aug. 17, 2013, in San Francisco. Emirates Team New Zealand won the race. The Golden Gate Bridge is visible in the distance. (AP Photo/Eric Risberg) ( Eric Risberg )

New Zealand's trouble was Luna Rossa's gift, allowing the Italians to win their first race against the Kiwis since they entered the round-robin portion of the Louis Vuitton Cup challenger series in early July. They are now tied 1-1 in the best-of-13 finals. The winner of the Louis Vuitton Cup will face defending champion Oracle Team USA in the 34th America's Cup beginning Sept. 7.

"That's not the way we like to win points, but I'm really pleased," said Luna Rossa helmsman Chris Draper, adding that his boat and his crew are performing much better than in past races. Still, Luna Rossa had a small problem of its own Sunday when a rib keeping the wing stiff cracked, but it didn't affect the race.

New Zealand was in control from the start and was widening its 300-meter lead heading toward the third mark when the hydraulics failed. The sailors aboard looked helpless as the boat drifted toward the Golden Gate Bridge, and Luna Rossa swiftly rounded the third mark and never looked back.

New Zealand quickly repaired its boat with a new battery pack from a chase boat and was ready to participate in the second race of the day. But winds on San Francisco Bay kicked up to unsafe conditions, and the race was canceled.

SAN FRANCISCO, CA - AUGUST 17:  Oracle Team USA takes practice before the start of race one of the Louis Vuitton Cup finals on August 17, 2013 in San
SAN FRANCISCO, CA - AUGUST 17: Oracle Team USA takes practice before the start of race one of the Louis Vuitton Cup finals on August 17, 2013 in San Francisco, California. Emirates Team New Zealand won race one after Team Luna Rossa Challenge did not finish. The winner of the Louis Vuitton Cup goes on to race against Oracle Team USA in the America's Cup Finals that start on September 7. (Photo by Justin Sullivan/Getty Images) ( Justin Sullivan )

Races 3 and 4 are scheduled for Monday, beginning at 12:10 p.m.

The New Zealand breakdown came a day after the team survived a dramatic nose-dive in its first race against Luna Rossa that broke the trampoline and the fairings and threw two sailors overboard. The team's shore crew worked into the night to be certain the nose-dive didn't cause any hidden damage. Davies said the battery pack issue was unrelated.

Earlier in Saturday's race, Luna Rossa also had equipment trouble. It's daggerboard delaminated and broke away from the pin holding it.

"These boats are really fragile," Luna Rossa skipper Max Sirena said Sunday, "and need a lot of maintenance."

Adding to the demolition mix was Oracle Team USA, which lost a rudder Sunday morning on one of its two boats as it headed to a scrimmage race. The problem began Saturday when skipper Ben Ainslie sailed past the St. Francis Yacht Club and turned to avoid a small yacht. The rudder hooked the line of the navigation buoy and "came to a pretty abrupt stop," Oracle Team USA general manager Grant Simmer said.

The boat sailed in two practice races after that, and the shore team repaired the superficial damage to the rudder overnight, but Sunday, it cracked clean off during preparations for a start against the boat skippered by Jimmy Spithill.

"There was more damage to the rudder than we thought," Simmer said. While Ainsley is surely disappointed he couldn't race Sunday, Simmer said, the damage to the rudder is "no big deal."

Still, he said, "these boats require a great deal of caution and care."

Contact Julia Prodis Sulek at 408-278-3409.

LOUIS VUITTON CUP FINALS

Emirates Team New Zealand 1
Luna Rossa Challenge 1

Best-of-13 series
Monday: Races 3 and 4, 12:10 p.m. and 1:10 p.m.
Wednesday: Races 5 and 6, 1:10 p.m. and 2:10 p.m. live on KNTV
Saturday: Races 7 and 8, 1:10 p.m. and 2:10 p.m. live on COZI TV, 4 p.m. on NBC Sports Network
Sunday: Races 9* and 10*, 1:10 p.m. and 2:10 p.m. live on COZI TV, 4 p.m. on NBC Sports Network
Aug. 28: Races 11* and 12*, 1:10 p.m. and 2:10 p.m. live on KNTV, 2 p.m. on NBC Sports Network
Aug. 30: Race 13*, 1:10 p.m. live on KNTV, 2 p.m. on NBC Sports Network
* -- if necessary
COZI TV is available on Channel 186 on Comcast Cable or broadcast digital Channel 11.2.