A roundup of the week July 1-7

BOXING—Undefeated JULIO CESAR CHAVEZ of Mexico retained his WBC junior lightweight championship with a second-round knockout of Roger Mayweather in Las Vegas.

CREW—At the 146th Henley Royal Regatta, Harvard defeated Princeton by 3‚Öî lengths to win the Grand Challenge Cup for elite eights. Britain's Steve Redgrave won the Diamond Challenge for single sculls by four lengths, beating Brad Lewis of the U.S. In the Princess Elizabeth Cup for schoolboy eights, St. Paul's School of Concord, N.H. lost in the final to Britain's Hampton School by one-third of a length.

PRO FOOTBALL—The defending champion Baltimore Stars edged the New Jersey Generals 20-17 in a quarterfinal matchup and advanced to the semis. There they beat the Eastern Conference-leading Stallions in Birmingham 28-14 to gain a place in the finals. Western Conference leader Oakland claimed the other spot in the championship game by defeating Memphis 28-19 (page 58).

GOLF—CURTIS STRANGE shot a nine-under-par 279 to win $86,506 and his third PGA event of the season at the 76th Canadian Open in Oakville, Ont. Jack Nicklaus and Greg Norman tied for second, two strokes back.

Nancy Lopez fired a final-round 68 for a seven-under-par 281 total to beat Allison Finney and JoAnne Carner by three strokes at the Hall of Fame Championship in Sugar Land, Texas. Her first-prize check was worth $45,000.

Seve Ballesteros shot a final-round 69 for a 21-under-par 263 total to win the French Open and $18,375 at St. Germain-en-Laye. Runner-up Sandy Lyle finished two strokes back.

HORSE RACING—MOM'S COMMAND ($3), ridden by Abigail Fuller, beat Bessarabian by 2½ lengths to win the Coaching Club American Oaks at Belmont Park. The 3-year-old, which won $142,560, became the sixth horse to win the New York Triple Crown for fillies (page 56).

Vanlandingham ($19.20), with Don MacBeth in the saddle, defeated Carr de Naskra by 8¾ lengths to win $180,600 in the Suburban Handicap at Belmont Park. The 4-year-old colt covered the 1¼ miles in 2:01.

Creme Fraiche ($4), Eddie Maple aboard, won the 75th American Derby at Arlington Park by a length over Red Attack. The 3-year-old colt covered the 1¼ miles in 2:01[3/5] and won a first-place purse of $96,000.

MOTORCYCLING—FREDDIE SPENCER, riding a Honda, beat 1984 world champion Eddie Lawson, on a Yamaha, by five seconds and Carlos Lavado of Venezuela, also on a Yamaha, by 12.7 seconds in 500-cc and 250-cc motorcycling events at the Belgian Grand Prix at Francorchamps. Spencer averaged 103.8 mph in the 500-cc race and 98.2 mph in the 250-cc competition.

MOTOR SPORTS—GREG SACKS won $45,350 by driving a Chevrolet Monte Carlo to his first NASCAR Grand National victory in the Firecracker 400-mile race in Daytona Beach, Fla. He averaged 158.730 mph on the 2.5-mile Daytona International Speedway tri-oval to beat Bill Elliott, in a Ford Thunderbird, by 23.98 seconds.

Al Unser Jr., in a Lola-Cosworth, defeated Geoff Brabham's March-Cosworth by 11.6 seconds to win a 220-mile Indy car race in Cleveland. The winner averaged 124.081 mph around the 2.48-mile circuit.

Brazil's NELSON PIQUET, driving a Brabham-BMW, won the French Grand Prix at Le Castellet, France by 6.7 seconds over runner-up Keke Rosberg of Finland, in a Williams-Honda. Piquet averaged 125 mph.

ROAD RUNNING—MICHAEL MUSYOKI finished in a course-record 27:58 at the 10K Peachtree Road Race in Atlanta, beating Joseph Nzau by nine seconds. Grete Waitz won the women's division by 30 seconds over Judi St. Hilaire in 32:03.

SAILING—The UNITED STATES, skippered by America's Cup veteran Gary Jobson, won the eight-nation Liberty Cup yacht racing series in New York Harbor. Australia, with Hugh Treharne, another America's Cup vet, at the helm, placed second in point accumulation.

Defending champion LARS HJORTNAES of Denmark won the Finn Gold Cup (the class world championship) in Marstrand, Sweden, beating the Soviet Union's Oleg Khoperski by 0.1 point.

TENNIS—Unseeded BORIS BECKER became Wimbledon's youngest champion when he upset Kevin Curren 6-3, 6-7, 7-6, 6-4 to win the men's singles title. MARTINA NAVRATILOVA defeated Chris Evert Lloyd 4-6, 6-3, 6-2 to win her fourth consecutive women's singles title. HEINZ GUNTHARDT and BALAZS TAROCZY beat Pat Cash and John Fitzgerald 6-4, 6-3, 4-6, 6-3 for the men's doubles championship. KATHY JORDAN and ELIZABETH SMYLIE upset Navratilova and Pam Shriver 5-7, 6-3, 6-4 in women's doubles, snapping their match-winning streak at 109. NAVRATILOVA and PAUL McNAMEE defeated Smylie and Fitzgerald 7-5, 4-6, 6-2 to win the mixed doubles (page 18).

TRACK & FIELD—MARY DECKER SLANEY ran an American-best 2:34.8 in a 1,000-meter race in Eugene, Ore. to break Madeline Manning's 1976 mark by 2.5 seconds.

TRIATHLON—Defending champion KEN GLAH of West Chester, Pa. was the men's overall winner in the third Liberty to Liberty Triathlon, a race that started in New York City and ended in Philadelphia, with a time of 6:43:57. KAREN MILLER of Philadelphia topped the women with a time of 7:41:37.

MILEPOSTS—FIRED: DON KLOSTERMAN, 55, as president and general manager of the USFL's ownerless Los Angeles Express, which finished the season at 3-15.

SIGNED: To a four-year contract beginning this fall with the Houston Oilers, running back MIKE ROZIER, 24, who has played the past two seasons for the USFL's Pittsburgh Maulers and the Jacksonville Bulls.

DIED: Montreal Canadien general manager from 1946 to '64, FRANK SELKE SR., 92, whose team set a National Hockey League record by winning five consecutive Stanley Cup titles from 1956 to '60; in Montreal.

Guy Bush, 83, a pitcher for 17 years in the major leagues, best known for having given up Babe Ruth's last home run on May 25, 1935; of cardiac arrest; in Shannon, Miss.

Ralph (Cooney) Weiland, 80, former Boston Bruin center and veteran Harvard University hockey coach, who had a 315-174-17 record and coached the Crimson to eight Ivy League championships; in Boston.

Shawn Thomas, a 26-year-old lightweight boxer from Detroit; of injuries suffered during a May 29 bout against Chris Calvin, 26, of Nashville; in Merrillville. Ind.