Sunday, the day before the Boston Marathon, word came from London that Grete Waitz had tied Allison Roe's world record: 2:25:29. Imagine running 26 miles 385 yards and tying the world record. That has to be harder than breaking it, everyone said.

Then came Joan Benoit, a wisp of a woman, whose assault on the record was anything but gentle. Her time Monday was audacious: 2:22:42. Ten men since World II have won the Boston Marathon in slower times than that; Amby Burfoot ran only 25 seconds faster when he won in 1968. She ran 13 minutes faster than her winning time in 1979.

"Joanie's an idol to me," said Greg Meyer, the men's winner (2:09). "It was a Beamonesque performance, his (long) jump. People are going to be chasing it for a while. Unfortunately, for them, I think Joanie can run faster."

Meyer says it is analogous to a man running 2:07:30. "Like breaking Alberto Salazar's record (2:08:13) by 30 or 40 seconds," he said. "People would say, 'That's incredible, measure the course.' "

"She has such an economical stride, such leg speed," said Jacqueline Gareau, who was second, nearly seven minutes slower. "I can't imagine how fast it is."

Nor could Benoit. "Deep down, I wanted to run 2:23 point something," she said. "Rumor had it that Allison was going to sit on my tail. I knew I couldn't play cat and mouse so I went right out." Roe dropped out at about 17 miles.

For the first 10 miles, Benoit ran at about a 2:16 pace. Male runners cautioned her to slow down. Her body told her something else: "I listened to what my body said. I never really figured it out on paper. I thought I'd run 32:30 through 10 kilometers and wanted to be 52:30 at 10 miles."

When she extinguished her U.S. record for 10 miles by running 51:38, she said, "What the heck, I'm just going to continue to run how I feel."

She felt fine until her feet began to blister in Natick, near the 10-mile mark. "Right before Wellesley Hills, I developed a stitch in my side," she said. "I slowed down the pace, I took some water, I collected myself and I moved onward."

She went by the half-marathon mark in 1:08:23, 39 seconds under her U.S. record, and 20 miles in 1:46:44. "I was fatigued from 24 on," she said. "But I was in control the whole way."

Her time has added credence to the argument that women are more physiologically suited to the marathon than men because they have more body fat to burn during the last, critical miles.

The progress in women's marathon times over the last decade has been stunning. In October 1975, Jacqueline Hansen, the last American to hold the world record, ran a 2:38:15, the first sub-2:40 marathon. Waitz broke the 2:30 barrier at the New York City marathon in October 1979 with a 2:27:33. Benoit, undoubtedly, will be among the competitors in the the first women's Olympic marathon in 1984.

Fred Lebow, director of the New York City marathon, does not think anyone will be able to challenge her record until after the 1988 Olympics.

Monday, Meyer was on world record pace, too. He slowed when he realized he would win, relaxed, savoring the experience. "People said, 'Why didn't you sprint to break 2:09?,' " he said. "I didn't care. Things went the way I wanted. It didn't matter . . . Everybody's concerned about times. Records like Joanie's, they just happen."

"I ran today to run," is how the 5-foot-3, 105-pound Benoit put it.

They met later at the awards dinner, friends who understood each other well. "There was nothing to say," Meyer said. "Everyone was just laughing and giggling. A couple of kids in the cookie jar."