Despite taxing temperatures in the mid-60s, much hotter than he prefers, and a brutal early pace that had him hurting and worried after 10 miles, Bill Rodgers won the prestigious New York City Marathon yesterday for the third consecutive year.

But the greatest glory of an idyllic Indian summer day - ideal for the onlookers, who police estimated at nearly 2 million in number, but too torrid for comfortable running - went to Grete Waitz, a 25-year-old Norwegian, who set a women's record of 2 hours 32 minutes 29.8 seconds in her first attempt at the 26-mile, 385-yard marathon distance.

Rodgers, 30, the Newington, Conn. native who now lives in Melrose, Mass., reasserted his status as the world's premier marathoner with the best race he ever has run in warm, humid weather - conditions in which he usually suffers more than most distance runners.

After covering the first 10 miles in a blistering 49 minutes flat - "an insane pace," he called it, forced upon him by challenger Garry Bjorklund - Rodgers finished in 2-12-12, 2:17 off the U.S. record of 2:09:55 that he set in winning the 1975 Boston Marathon, his first world class effort.

Rodgers' time yesterday was 2:03 slower than the 2:10:09 he ran on a drizzly, mid-40-degree day in 1976, setting the record for the character-rich New York course that starts on the Staten Island toll plaza of the Verrazano-Narrows Bridge and winds through diverse neighborhoods in all five of New York's boroughs before finishing amid the splendid autumn foliage in Central Park.

Rodgers pulled away from a spent and fading Bjorklund on the Queensboro Bridge, 15 miles into the race, just as he did last year. He opened a lead of perhaps five city blocks along First Avenue in Manhattan, from the fashionable pub district of the East 60s to 125th Street in Harlem.

Going into the deceptively steep entrance ramp of the Queensboro, which connects Queens and Manhattan, Rodgers had only a 15-foot lead. By the time he left the carpet which was laid over the bridge's open steel grating, he had more than tripled that.

At the 17-mile marker on First Avenue, where crowds estimated in the hundreds of thousands formed a narrow corridor and screamed encouragement to the by then pained and straining runners, Rodgers held a two-block lead over Bjorklund.

From there the champion, his sandy hair and arms bobbing in perfect rhythm with his ever-so-smooth stride, blew out the competition.

Rodgers stretched his lead to a quarter-mile at 18 miles, a half-mile at 19. From the CB radio in race director Fred Lebow's "pace car" emanated a scratchy message: "He'a all alone."

By the time Rodgers got to Central Park, where the maples lining the roadway were turning from green to stunning shades of gold and rust, Rodgers looked relaxed and almost serene despite stiffening calf muscles.

At the finish line in front of the Tavern on the Green at West 67th Street, an Air Force brass band played lively tunes and gaily painted dancing clowns entertained. Wall-to-wall people on either side of West Drive formed a patchwork quilt of fall fashions and colors in the summerlike afternoon. Their applause swelled, and they showered Rodgers with confetti as he crossed the finish line shortly after 12:42 p.m.

Bjorklund - a 26-year-old Minnesotan who was on the U.S. Olympic team in 1976 as a 10,000-meter man and is determined to win his first major marathon - "died," as distance runners say, at approximately 20 miles. Looking and feeling awful, he struggled guttily at a 77th place finish in 2:29:58.

Ian Thompson, 29, the supposedly over-the-hill Englishman whose 2:09:12 in the 1974 Commonwealth Games ranks as the third fastest marathon ever run, took second place in 2:14:12, 2:01 behind Rodgers.

Surprising Trevor Wright, 32, of Great Britain was third in 2:14:35; 2:16:54; and Thomas Anterak, 27, from Wisconsin, fifth in 2:17:12.

Jack Foster, 46, the former bicycle racer who didn't take up running until he was 33 out has represented New Zealand in the last two Olympic marathons, finished sixth in 2:17:29 to take the "masters" (over-40) title.

Waitz, a lnaky 5-7 1/2 110-pound language and physical education teacher from Oslo who holds the women's world record in the 3,000 meters, claimed the Amateur Athletic Union women's national championship in the marathons by topping the approximately 1,000 women is the field estimated at 9,000 total starters, more than any U.S. marathon.

She finished 105th overall.

Waite never had competed at longer than 16 kilometers (about 10 miles) - she won a race of that distance at Stockholm two weeks ago - but decided last week to accept on short notice an invitation to compete in what is rapidly supplanting Boston as America's top marathon.

Because of her late decision, Waitz was given number 1173 and was not even listed in the official program - the startled public address announcer at the finish line said, "No. 1173 has overtaken Martha Cooksey for the women's lead at 20 miles, but I don't know who she is" - but her time bettered by 2:17.7 the previous women's record of 2:34:47.5 set earlier this year by Christa Vahlensieck of West Germany.

Waitz, who arrived only Thursday for her first visit to the United States, was asked if she could run faster.

"It is difficult to say. I don't really know the distance. I haven't trained for it. I have been running only 17 to 19 miles a day," replied the cheerful Norsewoman. "I just wanted to try running a marathon because so many girls are doing that here. Only a few in Norway, but I read so much about the marathon in the Tract and Field News."

She was second behind Cooksey, the Avon International women's champ after 10 miles. "I couldn't see her, but I just decided to run faster," recalled Waitz afterwards, "and faster," recalled Waitz afterwards, "and at 20 miles I passed her. I don't know how she was feeling. I didn't want to look at her."

Cooksey, looking so ghostly it was ghastly, staggered home second among the women in 2:41.55. Fellow Californian Sue Petersen was third in 2:44:46.

Rodgers, who has won all five marathons he has entered since suffering in the heat and dropping out at Boston in 1977, seemed more asthonished by Waitz's effort than by his own finest outing in the heat (54 degrees at the start, 64 at the finish) and humidity (60 pecent) that worried him.

"She may have run a score sane race than the men did," said the 5-8 1/2, 129-pound Wesleyan University and Boston College School of Education graduate, a former teacher of retarded and emotionally disturbed children who now operates a thriving running boutique in Boston.

"I think we ran the first half much too fast, and then it was a matter of holding on. It was very intense early in the race. Bjorklund, Thompson and (New Zealander Kevin) Ryan set a berserk pace the first seven miles. I thought they were making a mistake . . . I was thinking ahead to the end of the race and wondering what any of us would have left."

Bjorklund moved ahead of Thompson for the lead in the eighth mile, and Rodgers went with him. "That was really the start of the race. I thought about holding back, but Garry looked so strong I thought I had to stay with him and hope that his inexperience in the heat hurt him," Rodgers continued.

"I had a feeling Garry was going to win today," Rodgers said of the man he outdueled and vanquished First Avenue, 16-20 miles into the race a year ago. "I was saying to myself, "No. 2 is pretty good. I'll come back next year." But at 10 miles, he faltered a little bit. I could sense it.

"We were running together, maybe 50 yards ahead, and he said, 'I'm not feeling too good.' I said, 'Me either. Let's cruise a little while.' At Queensboro Bridge, I made my move. But I don't think I broke him so much as he broke himself by going out so fast."