A roundup of the week July 14-20

BOXING—EDDIE MUSTAFA MUHAMMAD scored a 10th-round TKO over Jerry Martin to retain his WBA light heavyweight crown, in McAfee, N.J.

CYCLING—JOOP ZOETEMELK of The Netherlands finished 6:55 ahead of countryman Hennie Kuiper to win the 22-day, 3,949-km. Tour de France.

GOLF—TOM WATSON shot a 13-under-par 271 to win the British Open by four strokes over Lee Trevino at Muirfield, Scotland (page 22).

Pat Bradley shot a 13-under-par 206 to beat Nancy Lopez-Melton by a stroke and win the $100,000 Greater Baltimore Classic.

Scott Hoch defeated Curtis Strange by three strokes with a 14-under-par 266 to win the $200,000 Quad Cities Open in Coal Valley, Ill.

HARNESS RACING—NIATROSS ($2.80), driven by Clint Galbraith, defeated Storm Damage by 4¼ lengths to win the $1,011,000 Meadowlands Pace. The colt ran the mile in a 3-year-old pace record 1:53[1/5] (page 20).

HORSE RACING—WINTER'S TALE ($8.80), ridden by Jeffrey Fell, won the $217,000 Brooklyn Handicap at Belmont by five lengths over State Dinner. The 4-year-old gelding covered the 1½ miles in 2:28[3/5].

Spectacular Bid ($2.10), Bill Shoemaker up, beat Hold Your Tricks by 10 lengths to win the $259,800 Washington Park Stakes at Arlington. The 4-year-old colt ran a track-record 1:46[1/5] for the 1‚Öõ miles.

XXII OLYMPIC GAMES (page 10)—CYCLING: 100-kilometer, Men, 1) YURI KASHIRIN, OLEG LOGVIN, SERGEI SHELPAKOV, ANATOLI HARKIN (U.S.S.R.), 2) East Germany, 3) Czechoslovakia.

PISTOL SHOOTING: 50-meter, 1) ALEXANDER MELENTEV (U.S.S.R.), with a world record 581 points, 2) Harald Vollmar (East Germany), 3) Lubtcho Diakov (Bulgaria).

SWIMMING: 200-meter Butterfly, Men, 1) SERGEI FESENKO (U.S.S.R.), 2) Phil Hubble (Great Britain), 3) Roger Pyttel (East Germany); 4 x 100-meter Medley Relay, Women, 1) CAREN METSCHUK, RICA REINISCH, ANDREA POLLACK, UTE GEWENIGER (East Germany), in a world record 4:06.67, 2) Great Britain, 3) U.S.S.R.

WEIGHTLIFTING: 52-kilo class, 1) KANIBEK OSMONALIEV (U.S.S.R), 2) Ho Bong Chol (North Korea), 3) Han Gyong Si (North Korea), whose 113 kg. set a world record in the snatch competition.

SOCCER—NASL: Though eight teams were undefeated, all eyes were on two clubs—New York and Seattle—that hadn't won all week and were meeting on Sunday. The Cosmos won the encounter between two of the league's three best teams on a goal and an assist by league-scoring leader Giorgio Chinaglia. Earlier in the week, the Cosmos (17-7) lost to Philadelphia (7-16) for the first time ever, 2-1, and the Sounders (21-4) had their eight-game win streak snapped 3-2 by Washington (10-13). New England (14-10) ran its string of consecutive victories to nine, beating Rochester (10-12) 1-0 and Edmonton (11-13) 2-1. ASC Central-leading Chicago (18-6) also defeated the Drillers 2-1 before blasting Tulsa 7-1. While the Roughnecks (10-13) were losing their seventh straight, Dallas (11-11) saw its recent surge end in a pair of losses: to Portland (8-15) 3-2 in a shootout and 2-1 to Minnesota (10-13), who moved into second place in the NSC Central as Tulsa fell lo third. Tampa Bay (14-11) now shares the ASC-East lead with Fort Lauderdale (14-10). The Rowdies beat San Jose (7-17) 3-0 before losing to San Diego (12-11) three days later by the identical score.

ASL: Miami, which took over the American Conference lead by default when Sacramento went out of business early in the week, held on to the top spot despite being swept during a three-game road swing, losing 3-1 in New York, 1-0 at California and 3-2 at Golden Gate. National Conference leader Columbus got a 2-2 tie in Cleveland as Defender Daniel Mammana scored both Magic goals before losing to the United 4-2 in New York.

SWIMMING—PETER SZMIDT of Canada broke the world record in the men's 400-meter freestyle by .71 when he was timed in 3:50.49 in Etobicoke, Ontario. The previous mark was set earlier this year by Vladimir Salnikov of the U.S.S.R.

TENNIS—EDDIE DIBBS defeated Gene Mayer 6-2, 6-1 to win the $175,000 U.S. Pro Championship in Brookline, Mass.

TRACK & FIELD—MARY DECKER lowered by .3 of a second her own week-old American record in the women's 1,500-meter run when she was timed in 4:00.9 at the Liberty Bell Classic meet in Philadelphia (page 18).

Philippe Houvion of France established a world record in the pole vault with a leap of 18'11" in Paris. He surpassed the mark set earlier this year by countryman Thierry Vigneron by three-quarters of an inch. In the same meet, Craig Virgin broke the American record for 10,000 meters in 27.29.2, which was 10.2 seconds better than the mark he set in 1979.

Steve Ovett of Engalnd ran 1,500 meters in 3:32.1 in Oslo to tie the world record set last year by countryman Sebastian Coe.

MILEPOSTS—ELECTED: JUAN ANTONIO SAMARANCH, 60, an industrialist and the Spanish ambassador to the Soviet Union, as the eighth president of the International Olympic Committee. A member of the IOC since 1966, he succeeds Lord Killanin of Ireland.

HIRED: As coach of the NBA expansion Dallas Mavericks, DICK MOTTA, 48, the second-winningest active coach in the league, with a 541-443 record after eight seasons at Chicago and four at Washington. Ten of Motta's 12 teams have made the playoffs, including the 1977-78 Bullets, who won the NBA championship.

NAMED: As football coach at Army, ED CAVANAUGH, 51, to replace Lou Saban, who resigned last week after a 2-8-1 record in his only season. Cavanaugh, who had been Army's offensive-line coach, was the head man at Idaho State from 1968 through 1971, during which he had a 20-19 record, and was then an assistant under Saban for the Buffalo Bills until 1976.

DIED: Former Auburn football coach (1951-75) RALPH (Shug) JORDAN, 69; of leukemia; in Auburn, Ala. In his 25 seasons guiding the Tigers, they had a record of 175-83-7, including 12 bowl appearances and a national title (1957).

Henry A. (Ernie) Vick, 80, a catcher for the 1926 world champion Cardinals and an All-America center at Michigan in 1921; in Ann Arbor. He also played for the Chicago Bears in the late '20s and was a longtime official for the Big Ten.