Todd Martin faced two tough sets from qualifier Ramon Delgado before rallying for a 6-4, 5-7, 6-2 victory in a first-round match Tuesday in the ATP Championship in Mason, Ohio.
"That was the first time I've been on the court with Ramon," said the ninth-seeded Martin, who is 10-0 in first-round matches this year. "He's got a lot of shots."
Albert Costa, the 14th seed, also was challenged before prevailing 6-4, 3-6, 6-2 over Andrew Ilie.
No. 12 Nicolas Kiefer beat Sebastian Grosjean 7-5, 6-3 and 15th-seeded Nicolas Lapentti beat Vincent Spadea 6-2, 6-2.
Sixteenth-seeded Thomas Johansson retired from his match against Rainier Schuttler after aggravating a leg injury sustained while winning last week's du Maurier Open in Montreal.
Michael Chang improved his career record in Cincinnati to 36-9, the best of any active player, with a 6-3, 6-4 victory over Marat Safin.
"When I walked onto the court, I knew I was in a place where I've had some success," said Chang, a four-time finalist and two-time champion of this tournament.
Former No. 1 player Jim Courier improved his career records against Goran Ivanisevic to 8-3 overall and 5-0 on hardcourts with a 7-6, 6-2 victory.
At the Acura Classic in Manhattan Beach, Calif., seventh-seeded Barbara Schett beat Ines Gorrochategui 6-3, 6-2 and No. 8 Sandrine Testud was upset by Corina Morariu 6-1, 6-3.
Lisa Raymond eliminated Wimbledon semifinalist Mirjana Lucic, 6-3, 6-1.
SWIMMING: After a year away from competition, Amy Van Dyken resumed her medal-filled career by winning the 50-meter freestyle on the final day of the National Swimming Championships in Minneapolis.
Van Dyken, 26, finished the sprint in 25.13 seconds at the University of Minnesota Aquatic Center to earn her fourth national title. She hadn't competed in a national meet since the spring of 1998 after undergoing shoulder surgery.
Gary Hall Jr., a three-time medalist in the 1996 Olympics, finished the 50 in 22.13 to earn his fourth national championship. Hall, 24, was diagnosed with diabetes in March, missing the spring nationals, and was bedridden with the flu just five days ago.
SOCCER: The U.S. Soccer Federation has teamed with the Quaker Oats Co. to launch a new corn and oat-flavored cereal shaped like miniature soccer balls. The first boxes in early September will feature the World Cup-winning U.S. women's team. . . . Spanish club Barcelona said its Brazilian playmaker Rivaldo isn't for sale at any price, following speculation linking him with European champion Manchester United. Spanish newspaper El Mundo Deportivo reported that club chairman Josep Lluis Nunez said the team wasn't even considering listening to offers.
CYCLING: Danish cyclist Rolf Soerensen won the first leg of Tour of Denmark. Soerensen completed the 115-mile run Aalborg to Aarhus 17 seconds ahead of Italy's Nicola Loda and Lars Michaelsen of Denmark.
TRACK & FIELD: Pole vaulter Sergei Bubka, the only athlete to win six straight gold medals at the world championships, will miss the event this month because of injury. He is recovering from last year's surgery on his Achilles' tendon. . . . Donovan Bailey will skip the 100-meter sprint at the world track and field championship this month in Seville, Spain, but run the relay. He is recovering from a ruptured Achilles' tendon.
_ Compiled from Times wires.