A Roundup Of The Week Sept. 18-24

Bayakoa ($4.60), ridden by Laffit Pincay and carrying 125 pounds, won the Ruffian Handicap for fillies and mares, at Belmont Park, by 3� lengths over Colonial Waters, with 118 pounds. Bayakoa, a 5-year-old mare, raced the 1? miles in 1:48[2/5] to earn $135,840.

Norquester ($5.60), with Julie Krone up, came from fourth place after the final turn to win the Pegasus Handicap and $180,000, at the Meadowlands. The 3-year-old colt carried 114 pounds in beating Rampart Road (113 pounds) by a neck. He ran the 1? miles in 1:49[3/5].

MOTOR SPORTS—EMERSON FITTIPALDI, in a Penske Chevrolet, clinched the Indy-car driving championship in the season's next-to-last CART race, defeating Rick Mears, also in a Penske Chevrolet, by 4.796 seconds, in Nazareth, Pa. Fittipaldi averaged 134.767 mph for 200 laps of the one-mile oval at Pennsylvania International Raceway. He took home $46,960 for the race and $400,000 for the championship.

Gerhard Berger, driving a Ferrari, won the Portuguese Grand Prix, finishing 32.637 seconds ahead of Alain Prost, in a McLaren- Honda. Berger covered 71 laps of the 2.703-mile Estoril circuit in 1:36:48.546 for an average speed of 118.679 mph. Prost's second-place finish boosted his lead in the race for the Grand Prix driving title to 24 points over Ayrton Senna, who was knocked out of the race by a collision with Nigel Mansell.

Darrell Waltrip, in a Chevrolet Lumina, took the lead with 46 laps remaining to win a 500-lap, 263-mile NASCAR race at the Martinsville (Va.) Speedway. Waltrip averaged 76.571 mph on the .526-mile track, beating Harry Gant, in an Oldsmobile Cutlass, to win $55,650.

TENNIS—AARON KRICKSTEIN upset Michael Chang 2-6, 6-4, 6-2 to win a men's tour event and $59,500 in Los Angeles.

Martina Navratilova defeated Monica Seles 7-6, 6-3 to win a women's tour event in Dallas. The victory was worth $50,000.

WEIGHTLIFTING—At the World Weightlifting Championships, in Athens, ISRAIL MILITOSIAN of the Soviet Union set a world record of 352.5 pounds for the snatch in the 148.75 pound division, breaking his own mark of 349 pounds set last year.

MILEPOSTS—REVERSED: By the Appellate Division of the New York State Supreme Court, a lower court ruling that the San Diego Yacht Club violated the rules of the America's Cup Deed of Gift by using the catamaran Stars & Stripes in its 1988 victory over the monohull challenger, New Zealand. The decision means that pending an appeal by Michael Fay, sponsor of the New Zealand challenge, the club may keep the Cup and resume plans to host a defense in '92 (page 25).

DIED: SAL AUNESE, 21, former quarterback for the University of Colorado, who led the Buffaloes to an 8-3 record last season, his junior year, and set a school record of 92 passes without an interception; of cancer: in Denver.