Alinghi is racing Team New Zealand off the coast of Spain

Alinghi established an early lead after a fiercely contested opening, and Ernesto Bertarelli's crew did enough to hold on for victory.

With light winds making for good racing conditions, the teams were level on the first leg before Alinghi edged ahead.

Team NZ adopted an aggressive approach, but their efforts were thwarted.

The Kiwis launched a protest after the race over the way the Swiss team raise and lower their mainsail although Alinghi crew members said there was nothing unusual about their rig.

The win was much-needed for Alinghi after two successive defeats had left them trailing the challengers in the battle for sailing's most prestigious trophy.

The Swiss boat rounded the first mark with a 20-second lead after forcing Team NZ to the port-side, and extended their advantage to 35 seconds after a cautious second leg.

We're still sizing each other up Team NZ helmsman Dean Barker

The Kiwis cut the deficit back to 25 seconds by the final mark, but Alinghi held their own to seal the win.

"They're good all round. They go well, there's no question," said Alinghi skipper Brad Butterworth.

"It's a great regatta with the two best boats. The winds are highly volatile and it's a difficult racecourse.

"We've sailed well throughout this regatta. It's a tough school and these guys are good.

"We're enjoying the regatta. I think it's going to be close to the end and whenever we get a win it's a great day for us."

Team NZ helmsman Dean Barker said the teams were extremely evenly matched.

"We knew coming into this that Alinghi were going to be very strong. There's very little difference in performance and we're still sizing each other up," he said.