Peter Lundgren had never played Mats Wilander until yesterday and needed only 78 minutes to upset him in the ATP event in Mason, Ohio, 6-1, 6-4.

"To me, it seemed like he played really well," said Wilander, ranked No. 2 in the world.

Also gaining the quarterfinals: Boris Becker, Stefan Edberg, Anders Jarryd, Jimmy Connors, Brad Gilbert, Nduka Odizor and Mikael Pernfors. Pernfors beat Paul Annacone, 7-6, 4-6, 7-5, although he cut his head when he fell over the net and landed on his racket. He needed stitches but said he will not default to Becker . . .

Barbara Potter, who defaulted her doubles match earlier in the week with back problems, upset Hana Mandlikova, 6-4, 6-4, in the third round of the Canadian Open in Toronto.

"I could not have played with the same amount of physical advantage that I played with today if I had played doubles yesterday," she said.

Top seed Chris Evert routed Nathalie Tauziat, 6-2, 6-2, and third seed Pam Shriver, 10 pounds lighter, beat Kathy Jordan, 6-3, 6-3. "When I'm disciplined about food," Shriver said, "I feel disciplined about tennis."

Unseeded Helen Kelesi, playing before a home crowd, beat No. 7 seed Claudia Kohde-Kilsch, 6-2, 6-3.