SAN DIEGO – In light but unpredictable winds, Young America defeated the all-women America3 boat Tuesday and joined Stars & Stripes atop the America’s Cup defender scoreboard.

America3 led for the first half of the match, but Young America sailed the wind shifts better to rally back and finish more than 3 minutes in front.

“America3 is really pushing us to perform at a higher standard, always improving ourselves,” said Young America skipper Kevin Mahaney of Bangor.

“I think that is an important position for the defense (of the America’s Cup).”

Wind patterns that vacillated in direction and velocity all day played havoc on both the challenger and defender courses, causing huge winning margins and allowing, in one match, the slowest boat in the fleet to sail well ahead of the fastest.

In that race, the winless Spanish entry, Rioja de Espana, took advantage of a string of wind shifts to lead Team New Zealand, which has not lost a race. Team New Zealand, however, recovered to win by more than 20 minutes and remains ahead of the rest of the challenger boats.

“It’s pretty confusing,” said Team New Zealand’s Brad Butterworth. “It is just a matter of placing the boat where the best pressure is, but it’s pretty tricky.”

The America’s Cup boats now are off until the third round of racing starts next Tuesday.

After the second round, Young America is tied with Dennis Conner’s Stars & Stripes with 9 points, while America3, which won only one race in the second round, has 3 points.

Racing Tuesday began in a 7-knot breeze with Young America taking charge and forcing the women over the start line early. Young America claimed a 2-second lead and then picked up an early wind shift.

Halfway up the leg, the boats crossed, and Young America, with navigator and six-time world champion John Kostecki at the helm, had a three-boat-length edge.

But America3 was allowed to sail to the favored right side of the course, where it picked up a fresher second wind shift and moved ahead, taking a 46-second lead. Young America came back downwind to gain 28 seconds and keep the pressure on.

On the second leg, America3 moved out a little, but Young America eventually pulled in front and finished the second lap of the course 1 minute, 9 seconds ahead.

The Pact 95 boat added to its lead on the last leg and finished with a comfortable margin of 3 minutes, 2 seconds.

“We think we’ve moved forward this round,” said Mahaney. “We are tied for first place with Dennis and we’re ahead of America3. So that’s a pretty good place to be.”