Alinghi of Switzerland won the first race of the best-of-nine America's Cup regatta on Saturday when Team New Zealand had to withdraw because of gear breakage.

Part of the boom of the defending champion's vessel broke and a sail ripped loose, leaving Swiss challenger Alinghi to finish the first in the best-of-nine series on its own.

The New Zealand boat had made a powerful beginning to its title defence, outmanoeuvering Alinghi to the starting line in Hauraki Gulf off Auckland amid strong winds.

The home team, with the radical design innovations on their boat, were expected to adapt well to the weather.

But while heading down the first leg in the six-leg race, a carbon fibre piece designed to attach the tip of New Zealand's main sail to the boom snapped and then the jib sail ripped away from its stays.

We'll learn from this and we'll ensure we're better prepared next time TNZ Syndicate head Tom Schnackenberg

New Zealand syndicate head Tom Schnackenberg said he was confident the crew would come back from the disappointment.

"It's just a question of taking the positives out of this and taking care of the negatives and making sure that we learn our lessons," he said.

"It's a very strong group mentally and after a good night's sleep the guys will wake up in the morning and be ready to go racing as if nothing had happened.

"We'll learn from it and we'll ensure we're better prepared next time we meet these conditions."

Alinghi surged quickly to a five-minute lead even before they ended the first leg of the 34km course.

After trying unsuccessfully to replace its jib, Team New Zealand withdrew, leaving Alinghi to finish the course as required by the America's Cup rules to claim its first victory.

The second race will be sailed on Sunday.