Paul Cayard did what he set out to do, rattling the relatively inexperienced skipper on rival Prada into a grievous error in the opening minutes of America's Cup challenger finals today. It wasn't enough.

Prada, the sleek, silver and red Italian sloop designed by Doug Peterson, the same man who drew the lines for the past two Cup winners, was too quick for Cayard's AmericaOne and drew first blood in this best-of-nine, knockout round to select a Cup challenger.

Prada's 24-second win to take a 1-0 lead came after skipper Francesco deAngelis committed a costly foul in the prestart. The Italian crew spent much of last week practicing prestarts under the guidance of their coach, U.S. match-race expert Rod Davis.

But deAngelis wasn't ready for the move Cayard pulled with 1 1/2 minutes to the gun, letting Prada overtake from behind to put the Italians in an apparent controlling position. The crafty U.S. skipper, in his fifth Cup campaign, then swung the wheel to break the overlap when rookie deAngelis poked his bow too close. The boats tapped, on-water umpires flagged Prada for failing to give room for the windward boat to keep clear and the game was on for the Americans.

But not for long. Prada, swift in light to moderate winds, shot off the line into a favored breeze on the left side of the course and took a lead in 14 knots of southerly winds. Rules required deAngelis to make a 270-degree penalty spin to absolve his infraction, but he could do so any time in the race.

Up the sunlit Hauraki Gulf the two boats sped, side by side, Prada gaining in tiny increments on a mild, T-shirt day. By the first turning mark 3 1/4 miles upwind, deAngelis had a 25-second lead--3 1/2 boat lengths. Match racers reckon it takes 40 to 50 seconds to do a penalty spin, so he was still effectively behind.

As the boats turned downwind, Cup fans wondered how quickly AmericaOne could catch up. In five earlier meetings, the U.S. boat was quicker downwind, slower than Prada upwind. But winds stayed light, a boost to Prada. "Anything over 12 knots is good for us," AmericaOne mainsail trimmer Terry Hutchinson said beforehand. The breeze fell to 11, then 10, then finally 8 knots by the last leg.

In a softening breeze, Prada gained eight seconds downwind and turned back upwind with a 33-second edge. What happened next left match-race experts puzzled. Cayard, still close, tacked and split 2,000 yards away from Prada, hoping for different winds.

"AmericaOne is taking a big risk," veteran British match racer Chris Law said. "If you're in a penalty situation and in range, why would you risk getting out of range."

Almost as he said it, the wind shifted in Prada's favor. Approaching the third turning mark, the Italian lead was more than a minute, enough for deAngelis to spin through the 270-degree penalty turn and still keep a 25-second lead.

It was the halfway point in the race and a turning point for Prada. AmericaOne rallied on the last leg, closing to a boat-length behind as the breeze softened to a shifty 8 knots, then throwing a series of aggressive gybes to put the Italians off-balance. But Prada's tactics and boathandling were flawless; they matched AmericaOne gybe for gybe and the crucial, confidence-building win was in the books.

"They [Prada] did a great job of managing the race course," said AmericaOne operations chief, Olympic silver medalist Bob Billingham. "But it was nice to see our charge on the last run. It's good to know we can come back."

Today's win was a big step for Prada, which lost its last three outings against AmericaOne in preliminary trials.

Racing will resume Thursday and the weather is promising as a summer high-pressure system settles over "the land of the long white cloud." First team to win five advances to the 30th Cup match Feb. 19 against Team New Zealand.