Unseeded Mike Leach upset Stefan Edberg of Sweden, 7-5, 7-5, Wednesday night in the opening round of a $375,000 WCT tournament at Atlanta.
Top-ranked John McEnroe led an advance by five of the top seeded players by taking an easy 6-3, 6-3 first-round victory over Brian Teacher.
In other matches, No. 6-seeded Tim Mayotte defeated Hank Pfister, 6-4, 6-4; second-seeded Kevin Curren disposed of Tim Wilkison, 6-4, 7-5; fifth-seeded Scott Davis eliminated David Pate, 1-6, 6-4, 6-3; No. 8 Brad Gilbert defeated John Fitzgerald, 3-6, 6-3, 6-1, and Paul Annacone beat John Sadri, 6-3, 6-3.
McEnroe, the No. 1 player in the world and known for his outbursts on the court, was relatively quiet. He joked with fans and showed only a brief flash of temper when he pointed an accusing finger at a group of photographers he claimed were too noisy.
Top-seeded Martina Navratilova, who has won the $200,000 Chrysler-Plymouth Tournament of Champions every year since its inception, eliminated Kathleen Horvath in 75 minutes, 6-4, 6-1, at Lake Buena Vista, Fla.
Second-seeded Manuela Maleeva of Bulgaria also knocked out her opponent, Japan's top-ranked Esuko Inoue in straight sets, 6-2, 6-1 to advance to the quarterfinals.
The big upset of the second round occurred off the court Wednesday when eighth-seeded Sylvia Hanika of West Germany defaulted to Debbie Spence because of an ankle injury.
In the other matches, fifth-seeded Caterina Lindqvist fought off Michelle Torres, 7-6, 6-4; No. 3 Claudia Kohde-Kilsch topped Renata Sasak of Yugoslavia, 6-4, 6-3, and sixth-seeded Bonnie Gadusek downed Yvonne Vermaak of South Africa, 6-0, 6-4.
The Marbella Grand Prix men's Tournament at Marbella, Spain, was rained out for the fourth consecutive day.