Japan’s Chances Diminish : Sailing: Nippon retires after breakdown. Kiwis edge Il Moro.

Is this how it ends for the Nippon Challenge, with a sudden sayonara and a breakdown in Japanese technology?

Halfway through Wednesday’s windy race against France in the challenger semifinals of the America’s Cup--a race they needed to win, should win, were winning--their boat broke. A lousy rudder shaft snapped, leaving Chris Dickson and crew stranded in the fast lane. And the warranty hadn’t even expired.

That turned lead of about a minute into a 0-3 record with only six races remaining and New Zealand, Il Moro di Venezia and Ville de Paris all in front at 2-1 in the standings.

It was a devastating fall from the dizzying height of first place through the points rounds. Even with Dickson’s skill and a boatload of Samurai ethic and energy, Mount Fujiyama never looked as tall.

That incident boosted the other challengers’ race as a preview of the finals starting April 19. New Zealand defeated Il Moro by 18 seconds--only three or four boat lengths around the 20-mile course--and within six seconds of the biggest lead the Kiwis had all day.

On the defenders’ course, Dennis Conner drew the bye as Buddy Melges overcame an awful start, won a protest from the boss, Bill Koch, and sailed America 3’s newest boat, Kanza, to a 1:13 victory over America 3, the third boat.

That left Stars & Stripes and Kanza with three victories each, America 3 with none. Two will reach the finals.

The action reheats today. Stars & Stripes meets Kanza, and New Zealand comes right back against Il Moro. Desperate Nippon will be back out of the shop to race Ville de Paris again.

Dickson said, “About halfway toward mark five . . . (there was) a huge sound like a big tree falling down, followed by this very large noise. We lost control of the steering system.

“We started this semifinal knowing six wins were needed to get into the final, and we still have six more races to go. We intend to get those wins starting tomorrow.”

Dickson said he didn’t know why the carbon-fiber shaft broke, but the northwest winds blew up to 18 knots--unusually strong for San Diego--and probably put extra strain on the steering.

Tactician John Cutler dismissed the possibility of sabotage linked to the Le Defi Francais budget consultant being caught under the Nippon boat last Sunday.

“No relationship to the French diver,” Cutler said, “none whatsoever.”

The diver, who apparently was acting on his own, was summarily fired.

Melges’ start in the defenders’ intramural match was suspect. With no pressure to cross the line, some observers speculated that he jumped the gun on purpose to give Koch a 20-second head start. Melges denied it.

“I thought we had the guys hornswoggled,” Melges said.

He figured he was over by no more than “a foot and a half,” and added, “If there was any hanky panky, do you think I would have made him do a 270?”

He referred to an incident a few minutes later, after Kanza caught up to Koch’s America 3. Koch, approaching on port tack, without right of way, planned to tack on Melges’ lee bow but waited about half a boat length too late and came about directly in front of the hard-charging Melges.

Koch, whose helmsmanship remains open to question, might have suffered whiplash from a rear-end collision if Melges had turned his boat upwind, as Melges threw a protest flag against Koch for tacking too close.

The on-water umpires agreed, ordering Koch to do the penalty turn.

“I told him this morning, ‘I’m after your ass,’ ” Melges said. “ ‘You aren’t gonna get anything from me.’ He’s not gonna learn anything if we pussyfoot around. If that had been Dennis, I would have rammed him.”

Il Moro seemed to be following New Zealand on a tow line all afternoon, but Kiwi skipper Rod Davis never gave Paul Cayard room to pass.

New Zealand syndicate boss Michael Fay, aboard the team tender, told ESPN afterward, “I hope everybody now realizes this is the type of regatta we have on our hands. They’ll come home with a well-earned point tonight. There were some suggestions that it would be a cold dinner (otherwise).

“It’s going to be very, very hard. We’re in for some of the most exciting racing New Zealand has seen since we got in it in 1986.”

The Kiwis were rather businesslike at the finish, while four boat lengths later the losing Italians celebrated with hand-slaps and what Fay called “Euro-hugging.”

Apparently, the Italians were pleased to do so well despite breaking some battens in their mainsail during the pre-start jousting and having to change two tearing headsails during the race.

“Whoever’s gonna win the America’s Cup has another 23 races to go,” Cayard said.