Jan Gunnarsson of Sweden upset third-seeded Mikael Pernfors, 7-6, 1-6, 7-6, to advance to the semifinals of the $23l,000 Swiss Open tennis tournament at Gstaad, Switzerland.
Gunnarsson's opponent will be top-seeded Stefan Edberg, who defeated unseeded Damir Keretic of West Germany, 6-4, 6-1.
In other quarterfinal action, Emilio Sanchez of Spain eliminated Jakob Hlasek of Switzerland, 6-3, 6-7, 7-6, while the match between Roland Stadler of Switzerland and Tomas Smid of Czechoslovakia was interrupted by rain with Stadler leading, 4-2, in the first set.
Second-seeded Tim Wilkison advanced to the semifinals of the $117,000 Volvo Hall of Fame tournament by beating unseeded Val Wilder, 7-5, 6-2, at Newport, R.I.
Wilkison will play South African Eddie Edwards today in one semifinal match. Edwards defeated Marc Flur, 6-0, 4-6, 6-4.
Danie Visser of South Africa and Bill Scanlon of Dallas will meet in the other semifinal.