Alinghi, America's Cup champion, won the second day of racing.
Alinghi barely won the third race of Act 13 after cruising to a strong finish ahead of Desafio Espanol of Spain in the second race.
The Swiss boat couldn't keep tack as BMW Oracle Racing whipped around the final marker and into the lead in the late race. The American boat's turn of speed had been dominant, but the streaky conditions left it - along with many of the fleet - momentarily stationary 300 meters (yards) from the finish line as jib's failed to catch wind.
Alinghi helmsman Ed Baird finally found the breeze and was forced to tack at the finish line but still cleared it 14 seconds ahead of Italian team Luna Rossa. Desafio Espanol finished 29 seconds behind in third despite having been penalized after an early start.
"Up to that point we were having a good race and had a lead going down that run, we just didn't see it coming," BMW Oracle Racing trimmer Ross Halcrow said. "A few huffs were coming through and we got one big puff there that broke a symmetrical pole and one of our guys went over the side and we picked him up as we went by, though I don't know if anyone saw it."
A stewards' jury will meet later Wednesday to review protests filed by +39 Challenger and United Internet Team Germany that resulted in neither team finishing the race. +39 Challenger lodged its protest against United Internet Team Germany, while the German team lodged its against French syndicate Areva.
The Germans broke a rig as a result of a collision that took place at the first windward mark, while the Italian team's new mast snapped in three places two days after the team had worked through the night installing it.
Alinghi leads the standings with 33 points, five more than both BMW Oracle Racing and Emirates Team New Zealand. Desafio Espanol is fourth with 26 points.
Despite the last lap glitch, Halcrow said the American team was pleased since its performance could have been a lot worse.
"All in all we're pretty happy with the day," Halcrow said. "It's unfortunate the pole broke but we got without injuries, and we could have broken the mast."
And despite the sweep, Alinghi trimmer Simon Daubney believes the team still has some areas to improve on.
"We don't seem to be getting the starts we're looking for. Maybe we're just trying to hard to get the end we want but we always seem to be in the second row," Daubney said. "But it's a completely different thing from match racing and we're working on it."
In the early race, BMW Oracle Racing skipper Chris Dickson couldn't hold his USA 87 boat from crossing the start early, costing the American team an early penalty as the other 11 teams charged across the starting line.
Mascalzone Latino kept pace with Alinghi initially before skipper Vasco Vascotto was red-flagged for impeding the Swiss boat's progress in a crowded middle section of the course.
Dickson raced his boat up from eighth to fourth behind the New Zealand team as the breeze moved to the right, forcing the teams to come down on port gybe. Six teams were within a minute of the leader after the second turn.
A left hand shift of wind kept gave the leaders a comfortable downwind lead around the final marker, with the Spanish team holding its second-place position and BMW Oracle Racing unable to overtake the Kiwis and third place as it put up its symmetrical jibe in the rolling breeze.
"(Alinghi's) a great sailing team and still the team to beat, and the way they were sailing today proved it," Halcrow said.
With Alinghi's points not factored into the final standings, bonus points will be awarded to the 11 challengers following Act 13, which is worth triple points. The points are carried into the round-robin stage of the Louis Vuitton Cup, which could mean the difference in a tiebreaker.
The Louis Vuitton Cup, which takes place from April 16-June 11, will decide who challenges Alinghi for the America's Cup from June 23-July 4.