Courageous, which had a gigantic lead discounted Thursday because she could not complete the course within the prescribed 5 1/2 hours, belatedly seized a 2-0 lead over Australia today in the best-of-seven-race sailation for possession of the America's Cup.

But at least Australia's performance in the resailed second race was respectable enough to renew interest in a series that, like so many of the previous 22 challenges in the 126-year history of yacht racing's premier spectacle, had begun to look sadly like a match race between a Ferrari and an Edsel.

Courageous was never seriously threatened today by the challenger from the Sun City Yacht Club.The moderate breezes usually ranged from 10 to 15 knots on Rhode Island Sound, but occasionally slackened to as little as four or five knots.

However, after building a commanding two-minute lead on the first leg of the 24.3-nautical-mile course - which begins with a triangle made up of one leg into the wind and two "reaching" legs at 45-degree angles, followed by successive legs directly into, with, and back into the wind - Ted Turner and his defending crew could not make a rout of the second race.

Courageous's final margin of 1 minute 3 seconds was smaller than any she enjoyed in her 4-0 sweep over Southern Cross in 1974, with Ted Hood at the helm. The closest the Aussies came in '74 was 1:11, in the second race.

Having finally solved persistent problems with her sails - their shape, selection, and handling - Australia performed impressively, dispelling the notion that she simply was not in Courageous's league.

She picked up 1:02 on the downwind leg and engaged Courageous in a spirited tacking duel on the last weather leg, tacking 18 times.

Turner was content to cover Australia's maneuvers - the fundamental law of match racing is that once you get the lead, you play defense and stay between the opponent and the next mark - but even though she had no realistic hope of winning, the challenger had to be encouraged in terms of boat speed and handling.

"I think that today's race was an indication that Australia has the potential tow in races. The last three legs particularly showed that," said Alan Bond, the Perth real estate developer who first challenged with Southern Cross three years ago.

A. Lee Loomis, Bond's American counterpart as head of Courageous's syndicate, still expects to win in four straight but had one surefire signal of the Aussiess' expanding self-esteem.

"Australia did so well on the last leg that an important Australian came up to me and bet a case of whisky on tomorrow's race," Loomis said. But I have confidence in Ted Turner and the crew. I took the bet."

Neither side requested a lay day - Courageous is entitled to two during the first four races, while Australia has one left - so race No. 3 is cheduled for Saturday on the course nine miles out from Brenton Reef.

"We've lost one day already, and as much as some of us wanted to see the Brown-Yaye football game. I think some people would have been upset if we called a lay day for that reason," said Turner, 38, the Brown dropout who made a fortune in the billboard and television industries and owns the Atlanta Braves and Atlanta Hawks.

Bond, who took a day to regroup after Australia's 1:48 defeat in the opening race Tuesday, said, "We're here to race boats, not to have lay days. Our guys are getting hotter, and we don't want them to get cooled down."

Bond - a pudgy 5-foot-7 bloke with a twang that makes "Australia" sound like "Aus-trial-ya" and "sails" sound like "iles" - had said his crew would benefit from photos and video-tape of Thursday's non-race.

That one ended with the Aussie yachtsmen nearly a mile astern of Courageous, drifting airlessly in a breeze of only three knots, watching as Turner's men failed by just 550 yards to get across the finish line in time to make a major flogging official.

The Aussies were like Odd Fellows," one observer said, "lounging about on their annual fishing excursion."

Today Bond admitted, "There wasn't much to learn from those photos and video, really. I think we're very close to being able to win a race. Our sails are good; it's a matter of using them in the right way. We changed virtually nothing on the boat."