Their last race, the Boston Marathon, ended with a 300-yard sprint after a 26-mile run. Alberto Salazar won that one. The brash, unbeaten world-record holder, 24, beat Dick Beardsley by two seconds.

This morning, the two runners, who developed a healthy dislike for one another over the summer, will have a rematch in the New York City Marathon. At 10:30 a.m., with cannons booming and ABC cameras rolling (WJLA-TV-7), the two will lead 16,000 runners from Staten Island through Brooklyn, Queens, the Bronx and Manhattan in the 13th running of what has become the largest marathon in the country.

"If Alberto is human . . . he's beatable," said Beardsley, 26, who is known less for his running than for his bad luck. In the Boston race, for example, he tripped in a pothole, was blocked by a police motorcycle and almost was sideswiped by a press bus.

In 1970, when New York's marathon was run around Central Park, there was only one woman in a field of 126. This year, there will be about 2,500 women. The favorites are Grete Waitz, 29, three-time New York City Marathon champion from Norway, and West Germany's Charlotte Teske, this year's top female finisher in the Boston Marathon.

In her first marathon, in 1978, Waitz set a world record in the New York race. Teske has won four of her last five marathons. Last year's winner, Allison Roe, did not enter this year because of fatigue and an Achilles' tendon injury.

Winners of this year's marathon will earn national exposure and laurel wreaths. Those will be the official awards, anyway. Under-the-table cash prizes, which winners have reported receiving since 1978, are rumored to be available to the top dozen finishers again. Salazar was said to have received $14,000 in "expense" money for winning last year's race.

A new policy of awarding prize money to the clubs to which marathon runners belong, approved last month by the International Amateur Athletics Federation, had been expected to be used to reward this year's winners. A plan was approved by the board of directors of the New York Road Runners Club, which directs the marathon. But last week, Fred Lebow, the club president, said the payments would not be made because guidelines were too vague and future amateur eligibility might be endangered.

"I don't think we can afford to gamble," Lebow said at a news conference. "There were too many elements to consider and not enough time to work everything out."

One of those elements was the presence in the field of amateur runners from 68 countries. This year, for the first time, runners from the Soviet Union will compete in New York. The Soviets opposed changing amateur rules to allow indirect payments to athletes based on performance.

Weather should not be a major factor in this race. Forecasts call for sunny skies and temperatures in the low 50s. That will be ideal watching weather for the 2 million people expected to line the race route. The runners are always happy with nippy conditions.

Both Salazar and Beardsley like it cold and fast. They are front-runners with reputations for incredible mental toughness. The similarities end there. Salazar, a native of Cuba who lives in Eugene, Ore., was a track and field runner who specialized in the 5,000 and 10,000 meters.

Beardsley grew up milking cows on his family's farm in Minnesota. He began running marathons in college. He seems as mild-mannered off the track as Salazar is intense.

Rodolfo Gomez, 31, from Mexico predicts there will be more to this race than a duel between Salazar and Beardsley. "I want to win four marathons this year," said Gomez, who has won three. "I'll run with Alberto all the way."

Frank Shorter, who won the marathon gold medal in the 1972 Olympics in Munich and is credited with turning this country on to distance running, will be a dark horse. Shorter finished second in the 1976 New York race. The U.S. runner considered to have the best chance of finishing first among the women is Julie Shea, 23, from North Carolina. Shea is ranked No. 8 in the world. She finished fourth in Boston this year in her second marathon.