She burst upon the international track scene at the age of 12, a delightfully shy, pig-tailed pixie with braces on her teeth and a spectacular finishing kick that allowed her to set scads of age-group records and beat an occasional Russian or two, before she hit sweet 16.

Little Mary Decker, they called her then, as she whooshed past almost everyone in sight at 800 meters and 880 yards. She moved even faster, it was said, at first sight of television cameras, microphones and notebook pads. "Yes, I was kind of scared. I was just a litle kid, you know."

She was also a little kid running with pain. She was plagued by shin splints that hurt her so badly "there were times I couldn't even walk after a race." And so, at age 17, Mary Decker seemed almost resigned to never running again.

But Friday night in the Los Angeles Times Indoor Games there was no pain for Mary Decker, just a world record in the 1,000-yard run. In her first race in the U.S. in nearly four years, she won that event in 2:23.8, slicing almost three seconds off her own record set in the same meet in 1974.

Decker is 19 now, a sophomore at the University of Colorado, and there are no braces, no pigtails and no shin splints. She is calm and poised with reporters. And she may also have altered her running style, if Friday night's race is any indication.

As a child prodigy, Decker often laid back behind the leaders until the final lap before unleashing a dazzling finishing kick. Friday night, she opened a 10-yard lead after one lap, never trailed and was not seriously threatened, finishing 5 1/2 seconds ahead of Francie Larrieu. "I just wanted to get out in front and avoid all the pushing and shoving," she said. "It's been a while since I've run indoors."

In fact, it had been awhile since she has run competitively. The agony of those shin splints forced Decker to quit racing for most of the last three years. "I tried everything," she said. "I stopped once for a whole year, then I went out and would run for a month and it would come back again. I'd stop again, rest and try running, but it was always the same. It always hurt."

Finally, in July, a desperate Decker decided to undergo surgery. It was a cut and snip job, if you will, of muscle and tendons in both legs. She resumed training last fall, then started competing with some of her University of Colorado teammates in a series of races in Australia and New Zealand in December.

Decker posted a 4:08.9 clocking in a 1,500 meter race down under and ran 2:08.1 in an 800-meter event last week, both strong times this early in the season. She did not lose in seven races, and more important, "I was running and I felt great."

Her victory in the 1,000 Friday night before a wildly cheering crowd of 16,333 "removes most of the doubts," said Decker, who grew up in nearby Orange, Calif. "I had been away so long, I thought people would forget me. But they didn't. The crowd was terrific. I'm esctatic."

Decker believes her best race will probably be the 1,500 meters during the outdoor season and when someone asked her, "Where do you go from here?" her answer said it all.

"Only upward," she said. "No more pain, no more injuries and no more defeats."

Decker's performance was the highlight of the Times meet. In other major events, sprinter Houston McTear had his usual quick explosion out of the blocks and easily captured the 60-yard dash in 6:17, a shade off his world record 6:11 set last week in Millrose Games.

In the mile, Eamonn Coghlan sprinted past Filbert Bayi on the first turn of the gun tap and stretched out a five-yard lead at the finish for a 6 and stretched out a five-yard lead at the finish for a 3:59.6 clocking. Bayi, timed in 4:00.8, has not won a race indoors this season.