Here, where everyone flouts the odds, Muhammad Ali is poised to fool Mother Nature on Thursday night.

At an age when a requiem for the premier heavyweight of his time is being composed, the darling of the weight watchers has the over-30 generation exerting body English for him.

Larry Holmes, a mere mortal, is trying to lay to rest the ghost that has haunted him as part owner of the world heavyweight championship, denying him the recognition that goes with the notion that the title holder can lick any man in the world.

The fight, scheduled to start shortly after 10 p.m. (EDT), will be shown on closed-circuit television at the Capital Centre in the Washington, D.C. area.

Ali's bid for immortality as a four-time champion calls up the memory of Jersey Joe Walcott winning the title at age 37, "going on 45" as the gag had it, when he knocked out Ezzard Charles in 1951.

The odds are favoring Holmes at 7 to 5, but they can't measure the unconquerable will of an Ali who stewed in his own sweat until he went from 254 to 217 1/2 at the weigh-in. That left him only six pounds heavier than the 30-year-old champion.

If it is, indeed, "The Last Hurrah for Ali", as Don King has billed the promotion, Ali even in defeat would leave a legacy almost safe from future challenge -- three reigns as champion, despite intervening layoffs of three years and two years.

Now a member of boxing's 20-year club, Ali is breaking down his big finish "by miracles." He hailed today's weight announcement as the first miracle and warned listeners not to be late by stopping for a hot dog or they might miss the second miracle.

"There might be a knockout in the first round," he cautioned. "But his behind will be mine by nine."

Holmes hit the scales 20 minutes before the scheduled time and was gone before Ali arrived.

"I wanted this to be a meeting with Holmes," the challenger said. "This was his first sign of fear. . . All you suckers who have bet against me, you've lost. With my timing and reflexes, it should not go over nine rounds."

Holmes was hardly the image of one of Ali's psyched victims. At the announcement of his weight, 211 1/2, he smiled broadly and thrust both fists aloft and said, "Ali will fall. The old man won't go eight rounds . . . somebody got a question? . . . real quick."

He was asked why he weighed in so early and responded, "Because that's the way the commission wanted it." Holmes and his entourage paused on the podium for several moments as he raised a championship belt for veiwing and remarked. "This one cost $38,000, the old one $150."

His exit amounted to a "sneak weigh-in." After he left, promoter King tried to pacify disappointed media representatives who had evisioned a newsy confrontation with Ali.

"I didn't want them here together," King said.

Why not?

"I didn't want my fight to start here; I want it in the ring."

Although he was left with a sypathetic audience all to himself, Ali's performance was relatively brief in contrast to demonstrations of the past. He left an impression that he was not that unwilling to get away from the bally-hooing he had done for promoters so much in the past.

He no longer had to contend with Holmes' taunt about being "Porky the Pig," after his weight was certified.

If the smiling champion seems at ease in the surroundings, it probably was because the undefeated title holder from Easton, Pa., has fought nine of his 11 bouts in Las Vegas, all but one at Caesars Palace.

A former sparring partner for Ali, Holmes has equaled Joe Louis' record with seven successive defenses of his World Boxing Council championship by knockouts. In winning all 35 of his bouts, Holmes has knocked out 26 opponents.

While Ali has not fought in the two years since he regained his title from Leon Spiks on Sept. 15, 1978, in New Orleans, Holmes has kept busy since decisioning Ken Norton for the title June 9, 1978. Holmes has fought three times this year, knocking out Lorenzo Zanon in February, Leroy Jones in March and Scott LeDoux in July.

Yet he has a reputation for tiring after the eighth round.

After beating Spinks for the World Boxing Association championship, Ali retired. Then, after Holmes won the WBC version from Norton the same year, John Tate defeated Gerrie Coetzee for the WBA title in 1979 and lost it to Mike Weaver this year.

Ali has been knocked down only four times in winning 56 to 59 bouts, 37 by knockouts.

Sonny Banks, Henry Cooper, Joe Frazier and Chuck Wepner hold the distinction of putting down Ali.

Ali's only losses were to Frazier by decision in their first bout; to Norton, when he suffered a broken jaw while losing a decision in the first of their three bouts, and to Spinks by decision in their first of two bouts.

The bout will be conducted under a 10-point-must scoring system. Three judges will vote, but not the referee, and the scores must be submitted by the judges after every round. The fight won't automatically end if one of the boxers is knocked down three times in one round.