A roundup of the week July 26-Aug. 1

BOXING—Korea's YUM DONG-KYUN won a split decision in Pusan over Rigoberto Riasco of Panama and was declared, pending WBC review, super bantamweight champion when American Referee Larry Rosadilla reversed his original verdict and told clamoring fans he had misread his scorecard.

PRO FOOTBALL—In the first week of exhibition play, the champion Steelers coasted to a 24-14 win over New Orleans. Juiceless Buffalo fell to Detroit 20-17, and Calvin Hill made his Redskin debut as Washington beat Atlanta 17-10. John McKay's first game as coach of the Tampa Bay Buccaneers was ruined by the Rams, 26-3; reserve Quarterback Don Strock led the Dolphins to a 16-3 victory over the Vikings, and Baltimore routed Cleveland 21-0. Fred Steinfort, heir apparent to George Blanda, booted a 27-yard field goal to give Oakland a 17-14 win over Dallas. After a scoreless first quarter between a pair of last season's losers, San Diego charged to a 20-7 win over Philadelphia. Joe Namath and Richard Todd shared quarterback but couldn't save the Jets from a 13-12 defeat by St. Louis, and Denver fell to Chicago 15-14. Archie Griffin rushed 12 times for 49 yards, and reserve Ed Williams scored two second-half touchdowns to carry Cincinnati past Green Bay 23-17. Seattle fell to San Francisco 27-20, and New England trounced the Giants 13-7 in overtime.

GOLF—BRIAN (Buddy) ALLIN posted his first PGA victory in two years, edging Ben Crenshaw by one stroke in the $200,000 Pleasant Valley Classic in Sutton, Mass. His seven-under-par 277 included a one-under 70 for the final round.

HARNESS RACING—STEVE LOBELL ($8.80), driven by Billy Haughton, won the $202,004 Yonkers Trot at Yonkers Raceway, N.Y., first leg of the trotting triple crown, in 2:01[4/5].

Keeping it in the family, Peter Haughton drove WINDSHIELD WIPER ($6.40) to victory in 2:01[2/5] in the Gaines Memorial Pace at Vernon Downs, Vernon, N.Y.

MOTOR SPORTS—JAMES HUNT of England, leading from start to finish in his McLaren-Ford M23, won the 50th German Grand Prix at Adenau, West Germany. World champion Niki Lauda is in critical condition after suffering extensive injuries when his Ferrari spun off the track and burst into flames.

A. J. Foyt, pole sitter in both the Indy and stock-car portions of the Twin 150s at the Texas World Speedway in College Station, won the Indy part in his Coyote-Ford at an average speed of 172.885 mph after qualifying at 207.314 mph. He then drove a 1976 Chevelle to victory in the USAC stock-car event, averaging 115.981 mph.

Richard Petty won his first Grand National stock-car race since February, fending off Buddy Baker for a 50-yard victory and averaging 115.875 mph for 500 miles on the 2.5-mile Pocono (Pa.) International Raceway trioval in his Dodge. Baker's second-place earnings of $13,465 made him the fifth $1-million winner in NASCAR history, joining Petty, David Pearson, Cale Yarborough and Bobby Allison.

OLYMPIC GAMES—World records continued to fall as the Games of the XXI Olympiad drew to a close. Decathlon winner BRUCE JENNER of the U.S. scored a new high, 8,618 points. Sweden's ANDERS GARDERUD set a world mark of 8:08.02 in the 3,000-meter steeplechase, and MIKLOS NEMETH of Hungary threw the javelin 318'4". VASILY ALEXEYEV of the Soviet Union lifted an Olympic-record 408 pounds in the snatch, then had a world-record clean and jerk of 562 for a total of 970 and a gold. IRENA SZEWINSKA of Poland ran the 400-meter dash in a world-record 49.29. In the 800-meter run, TATYANA KAZANKINA of the Soviet Union, who came in first, and NIKOLINA CHTERENA of Bulgaria, silver medalist, both bettered the world mark with times of 1:54.94 and 1:55.42 respectively. The East German 4x400 relay team of DORIS MALETZKI, BRIGITTE ROHDE, ELLEN STREIDT and CHRISTINE BREHMER set a record of 3:19.23; and LUANN RYON of the U.S., who won the archery gold medal with a total score of 2,499 points, had a world-record single round of 1,282. Finland's LASSE VIREN became the first man to win the 5,000 and 10,000 meters in two consecutive Olympics, then went on to finish fifth in the marathon. VIKTOR SANEYEV of the Soviet Union became the first triple jumper to win the event at three straight Olympics, and ALBERTO JUANTORENA recorded another first when he won both the 400 and 800 meters.

SOCCER—NASL: With two weeks of the regular season left, six of the 12 playoff berths have been claimed. Vancouver's two victories, over Philadelphia 3-1 and St. Louis 5-0, assured the Whitecaps of a spot, with the others going to San Jose (which beat Miami 3-0), New York, Tampa Bay (the Rowdies shut out Hartford 7-0), Chicago and Minnesota. In the Cosmos' 4-0 win over Dallas, George Chinaglia scored three goals and now trails league leader Derek Smethurst (42 points) by five, with Pelé in third place six behind.

ASL: Los Angeles became the first team to clinch a playoff berth when the Skyhawks beat Utah 3-0. It was Brian Parkinson's eighth shutout of the season and the team's 11th. Utah split two with Oakland, losing 3-2 and winning 1-0. Tacoma downed Sacramento 6-0 and then routed Oakland 9-0, with Brooks Cryder and Windsor Del Llano each getting three goals and Dave Chadwick two goals and one assist. Chadwick's season total of nine goals and seven assists leads the league. New York moved into first place in the East by beating Rhode Island 2-1. In New York's game with New Jersey, Apollo Peter Tavares was banned from the club and suspended from playing soccer for two years for attacking a referee who had ejected him from the game.

TENNIS—WTT: Defending champion Pittsburgh started the week in fourth place and climbed to third in a bid for a playoff berth. The Triangles beat Phoenix 29-20, but lost to second-place Cleveland 29-24 as Martina Navratilova handed Evonne Goolagong a surprising 6-0 defeat. They then downed Indiana 25-24 and Golden Gate 28-22 and now trail Cleveland by one game. In the Western Division, Phoenix had its share of problems as flu-stricken Chris Evert missed three matches, and the division leaders lost to Pittsburgh, twice to Hawaii (31-18 and 32-24) and 28-26 to New York. Second-place Golden Gate won its match with New York 29-27.

MILEPOSTS—HIRED: RON ROBERTS, 32, who guided the Georgia Southern team to NCAA tournament qualification four straight years, as golf coach at Wake Forest.

HONORED: JOHN SHUMATE, Buffalo Braves forward who missed the 1974-75 season because of illness, then came back to finish second only to Wes Unseld in NBA field-goal percentage shooting last season, with the Maurice Stokes Award.

RETIRED: MIKE BASS, Washington Redskin starting cornerback who played in 104 consecutive games since 1969, as the result of a neck injury suffered last season.

DIED: GEORGE SOUDERS, 75, who as a rookie won the 1927 Indianapolis 500 after starting 22nd, driving a Duesenberg at an average speed of 97.545 mph: in Lafayette, Ind.