ROME, JULY 22 -- Said Aouita of Morocco ran the 5,000 meters in 12 minutes 58.39 seconds at the Golden Gala track and field meet tonight, breaking his world record and the 13-minute barrier for the distance.

Aouita said he was unaware he was going so strong, otherwise he could have done even better in improving the 13:00.40 he set in 1985.

"I knew I was doing well," Aouita, 26, said. "But had I realized I was in such good form I'd have tried to run in 12:50. I could have done it."

Aouita was ahead of his record pace from the start, generating wild enthusiasm from the Olympic Stadium crowd of 40,000. He was paced for the first two-thirds of the race by Ibrahim Boutaib of Morocco and Fethi Baccouche of Tunisia.

Boutaib, silver medalist at the world junior championships last year, led for the first half of the race. The three, all dressed in yellow, appeared to run like a train, with great synchronism, and they soon were alone.

The first kilometer was run in 2:35.35 and the time after the second was 5:13.03, just under Aouita's time in 1985. Then Boutaib quit and Baccouche took the lead for almost another kilometer.

It was the turning point of the race. When Baccouche stopped, Aouita was nearly five seconds under his old time. The time after 3,000 meters was 7:46.37, and Aouita was out all alone for the last 1,600 meters.

He was clocked in 10:26.05 after four kilometers and strode home 50 meters clear of the pack.

"I am the greatest runner in the world!" Aouita shouted after completing a victory lap around the stadium with Boutaib and Baccouche, all carrying a huge Moroccan flag.

In addition to his world record in the 5,000, Aouita owns the records in the 1,500 meters, the two miles and the 2,000 meters. He set the 2,000 mark in Paris last Thursday with a time of 4:50.81.

"After running in Paris I was really tired. That's why I had come here just to win, and not really confident that I could break 13 minutes," Aouita said. "In these days, I have returned to Casablanca to train hard, and it has apparently done it for me."

Aouita said he had not yet decided what distance he would run at next month's world championships here. He could enter any race from the 800 to the 10,000 meters.

In other events of this 11th event on the IAAF Mobil Grand Prix circuit, Calvin Smith of the United States won both men's sprints, the 100 meters in 10.15 and the 200 in 20.22. Another American, Tonie Campbell, won the 110-meter hurdles in 13.31 and another, Gwen Torrence, took the women's 100 in 11.31. Robert Emmiyan of the Soviet Union took the men's long jump at 27 feet 8 3/4 inches and France's Thierry Vigneron of France the pole vault at 19-0 1/4.

In the 400-meter hurdles, Amadou Dia Ba of Senegal beat Americans Kevin Young and Danny Harris. Dia Ba finished in 48.12, Young in 48.72 and Harris 48.74.

New Zealand veteran John Walker won the 1,500 in 3:34.79, catching Alessandro Lambruschini of Italy (3:35.27) in the last 50 meters.