John Bertrand knew it was coming. "I don't think you'll see any more conservative starts from Dennis Conner," said Australia II's skipper. "He's not having a lot of success."

At high noon today in a smoky haze on Rhode Island Sound, Conner abandoned meekness with a vengeance. He won the start with a daring, improvised maneuver seconds before the gun and 3 1/2 hours later had put Bertrand and the Australian America's Cup challenge on the brink of elimination, trailing, 3-1, in the most competitive series in half a century.

If Conner wins Wednesday, the best-of-seven series will be over and the treasured silver cup America hasn't lost in 132 years will be safe in the New York Yacht Club for another four years.

Conner's red 12-meter yacht Liberty led all the way, but never by more than a half-dozen boat lengths as the boats proved almost dead even in speed in a slowly building southwester.

The victory squelched a growing confidence among the Australians, who had beaten Liberty 3 minutes 14 seconds in moderate airs on Sunday. Australia II's designer, Ben Lexcen, remarked afterward that his team was ready to "clean their (Liberty's) clock" in any wind conditions.

But it was another clock that did in Australia II today--the starter's clock. And though Liberty crossed the finish 43 seconds ahead of the white Australian challenger, this race was essentially decided before the starting gun sounded.

"To understand the start you have to understand a little about sailboat racing," said a grinning Conner. But only one rule actually applied--the rule of right of way--and Conner didn't have it.

In yacht racing, when two boats converge the right of way is arbitrarily assigned to the one on the so-called starboard tack, with the wind coming over the right side of the boat.

But with one minute to the gun Conner found himself charging for the line on a defenseless port tack while Bertrand advanced with the right of way, presumably on a collision course.

"Our plan was to duck under Australia's stern," said Liberty navigator Halsey Herreshoff, which would have put Liberty even at the start, at best. "But then we realized Bertrand was going to be late to the line. Dennis, as he's done so well all summer, just improvised."

Conner, carrying as his right of way only the confidence that he could make it, powered up and squeezed past the pointed bow of advancing Australia II. He was off and racing with a six-second lead.

"It was purely a judgmental error on my part," admitted Bertrand. "We were late to the start. We made the wrong choice at exactly the wrong time." And Conner capitalized.

The question then became whether Australia II, which had been faster than Liberty on every point of sail in lighter airs Sunday, would sail back into the lead on boat speed alone.

Conner, using a new mainsail and playing the wind perfectly, even by Bertrand's postrace assessment, staved off Australian advances on the first leg and rounded the first mark of the six-leg race 36 seconds in the lead. It marked the first time in the series that Liberty had reached the first mark ahead of Australia II.

He hung onto the lead all day in breezes of 10 to 15 knots, and shot over the finish to a cacaphony of horn blasts and cheers from the spectator fleet and a hat-waving greeting from New York Yacht Club officials watching from the motor yacht Foxhunter.

Liberty's sudden competitivenes after the drubbing she took Sunday puzzled some Australian observers who wondered if she'd been modified during Monday's day off. A few suggested her ballast might have been tampered with.

But Conner said no changes were made to the boat and when he was asked what he'd done with the day off, answered with a smile, "Worried."

Sail trimmer John Marshall said the difference in today's performance was that the winds were significantly stiffer, even though they measured only slightly higher, and Liberty likes a stiff breeze.

"What we were seeing today was a wind that was steady from top of the mast down to the deck," rather than one that gave out on lower portions of the sail, Marshall said. "It's a lot more powerful even though it doesn't show up on the instruments," he said.

More stiff sailing breezes are expected Wednesday for what could be the final day in this intriguing America's Cup summer. The forecast calls for more southwesterlies, but this time at 15 to 25 knots instead of 10 to 15.

By all acounts that's a Liberty breeze, but the Aussies continue to be convinced they can beat the Americans in a blow. Today they showed their boat is at least equal in a steady wind.

"It's obvious these boats are very, very close," said Bertrand, "and any boat that makes more mistakes than the other, pays."