All three top teams in America's Cup challenger trials clung to perfect records for one more day today as AmericaOne, Young America and Prada each scored easy victories. But the unbeaten strings must end Thursday when the three titans clash for the first time.

None of the three was seriously tested today as winds on the Hauraki Gulf finally puffed up to the range in which all the boats were designed to excel. By midafternoon a cool nor'easter was humming at 14 knots and the tall, slender boats were heeled and throwing sunlit spray, the first time crews have seen a breeze so strong since racing began Monday.

"It's cold out there," said Marcus Hutchinson, an official of the Louis Vuitton Cup organizers who rode as a nonparticipating 17th man on the French entry Le Defi Francais. "When you're going upwind, the breeze and your boat speed combine to feel like 25 knots across the deck."

That cool, refreshing breeze was not enough to push Le Defi ahead of the New York Yacht Club's charcoal gray Young America, which improved to 5-0 with an easy, 2-minute 4-second win over the French.

Young America skipper Ed Baird, former world match-racing champion, showed his credentials by forcing France's Bertrand Pace outside the start box as the gun sounded; Baird charged up the course with a full head of steam while Pace spun his boat a full 360 degrees and wasted over a minute fighting his way back upwind to the line.

"Basically, it was over right then," said Hutchinson, who had a two-hour boat ride to enjoy before the finish ended the exercise. It was the second straight day Baird had forced a competitor over early; he did the same to skipper Jochen Schumann on the winless Swiss entry FAST 2000 on Tuesday.

The sleek, silver Italian boat Prada (6-0) meantime was easily dispatching Spain's Bravo Espana in the morning and Dawn Riley's America True in the afternoon, while Paul Cayard's AmericaOne (5-0) had an easy time with the French Le Defi in its only race in the afternoon session.

If challenger trials are rapidly developing into a three-boat fight for the top, more will be known about these three on Thursday when Prada takes on AmericaOne in the morning, then Young America in the afternoon. Cayard, Baird and Italian skipper Francesco de Angelis finally get to test their boats and crews against their fellow front-runners. The big drama today came from another famous U.S. team, Dennis Conner's Stars & Stripes, which is still battling to find its place in the 11-boat challenger fleet. Conner, the eight-time Cup veteran, barely beat the French on opening day, then lost back-to-back to Hawaiian entry Abracadabra and Bravo Espana on Day Two. Some wondered if Conner's newest boat and low-cost, bare-bones Cup program was overmatched.

But today Conner's team under helmsman Ken Read beat back a spirited run by the respected Japanese entry Nippon in the best race of the day, then returned to the winner's circle in the afternoon, beating the winless Swiss to improve Stars & Stripes' record to 3-2, fourth best in the fleet.

Conner's team had good speed off the line after an even start and pushed the Japanese back by 26 seconds at the first turning mark three miles upwind. Nippon skipper Peter Gilmour, the most aggressive sailor in the fleet, came roaring back downwind to catch the dark blue San Diego boat just as the two approached the second turn.

Gilmour pushed Nippon's bow inside Stars & Stripes' line as the boats started the turn to go around the leeward mark and head upwind, but judges ruled he was too late establishing right of way, so he was flagged for a penalty. Worse, as his crew dropped the spinnaker while rounding, it dropped too quickly. The sail touched the buoy for another violation, and suddenly Gilmour went from dead even halfway through the race to deeply disadvantaged.

"I thought I was in a 30-footer instead of an 80-footer," said a sheepish Gilmour afterward. "It was definitely an 80-footer," responded Read. "I thought I was going to have to eat about 10 feet of it."

Each violation required Gilmour to spin the boat through a 270-degree penalty turn. By the time he hadd completed the first, he was out of range to catch Conner. The spectacular rounding proved the first of two costly mistakes for Gilmour and his crew. Later, bowman Toshiki Shibata was hit in the head by the spinnaker pole when a fitting opened. He broke his nose, lost several teeth and was being checked for a possible broken jaw and back injuries.

Conner's upbeat showing restored his flagging status among the half-dozen boats vying for spots in January's semifinals. It's still early, but most experienced Cup observers reckon Prada, AmericaOne and Young America are certain to make the six-boat semis. It also appears Young Australia, with the oldest boat, youngest crew and smallest budget in the regatta, and winless FAST 2000, which today became the only team to lose to Young Australia, are out of the running.