Edwin Moses, whose only problem was an untied left shoelace, ran away with the 400-meter hurdles at the World Track and Field Championships today, but Alberto Salazar finished a surprising last among 17 runners in the 10,000 meters.

Moses, 27, won his 89th straight race and 81st straight final; he has not lost in six years. Today, he finished in 47.50 seconds, well off his world record of 47.13.

European champion Harald Schmid of West Germany, the last to beat Moses, won the silver medal in 48.61. The Soviet Union's Aleksandr Kharlov edged Sweden's Sven Nylander for the bronze.

Moses was first over the first hurdle and never trailed. His major concern came when the shoelace became untied while he was sprinting down the home straightaway.

"I had no problems running," he said. "Technically, it was a very good run and I am pleased with the time. I tied the lace up before the race and there was nothing I could do. For a second--no more--I thought about it, but then I continued to run. I expected to win but, of course, you never know until the end of the race."

Andre Phillips of Los Angeles seemed set for the silver medal, but Schmid suddenly moved into contention when Phillips stumbled over the next-to-last hurdle and landed badly. Schmid went past him, followed by Kharlov and Nylander.

Alberto Cova of Italy produced a dramatic final burst to win the 10,000-meter gold medal in 28:01.04.

The U.S. team had a poor showing in the race as Mark Nenow of Lexington, Ky., was 13th in 28:17.28 and Bill McChesney was 15th in 28:34.46. Salazar, the marathon record holder whose U.S. 10,000 mark stands at 27:25.61, came in in 28:48.42.

Salazar said afterward he had changed his mind about attempting a 10,000 meters-marathon double at the 1984 Olympics and would concentrate on the marathon for the Games.

Tamara Bykova of the Soviet Union won the women's high jump at 6 feet 7 inches. Ulrike Meyfarth of West Germany was second at 6-6 1/4 and Louise Ritter of the United States won the bronze medal at 6-4 3/4.

The men's 800-meter final was the tightest race yet in the meet, with Willi Wulbeck of West Germany clocking 1:43.65 to win his first major title since the 1971 Europa Cup. Rob Druppers of Holland finished in 1:44.20 for second place, seven-hundredths of a second ahead of Joaquim Cruz of Brazil.

Jarmila Kratochvilova of Czechoslovakia, back on the track 35 minutes after qualifying for the 400-meter final, won the women's 800 in a rapid 1:54.68.

The 4x100-meter relay heats featured the awesome sprinting power of Carl Lewis, Calvin Smith and Emmit King--who finished 1-2-3 in Monday night's 100-meter final--and hurdler-football star Willie Gault. The U.S. team returned the fastest heat time of 38.75 in easing into the semifinals. The United States set the record six years ago at 38.03.

The U.S. quartet, which finished .65 seconds ahead of second-place Italy, looked impressive despite poor handoffs between King and Gault, and Gault and Smith. However, China, Kenya and Canada were all disqualified in the heat.

The two other heats were won by the Soviet Union (38.77) and East Germany (39.22).

Lewis, the winner in the 100 meters, later continued his quest for three gold medals when he was the leading qualifier for the long jump with a leap of 27-5 1/2. Jason Grimes of Knoxville, Tenn., was second-best at 27-2 1/2 and Mike Conley of Chicago became the 10th of the 12 finalists with a 25-11 mark.

Sergey Litvinov of the Soviet Union won the day's final gold medal, the hammer throw, at 271-3.