Top-seeded Mats Wilander and three other Swedes clinched quarterfinal berths in the $315,000 West German Open tennis championships Thursday at Hamburg, West Germany.
Wilander required 2 hours 4 minutes to beat Michael Westphal of West Germany in a third-round match, 4-6, 6-4, 6-3, and was joined by countrymen Jan Gunnarsson, Henrik Sundstrom and Joakim Nystrom.
The draw so far has kept the Swedes apart and all four could advance to the semifinals.
Gunnarsson upset defending champion Juan Aguilera of Spain, 7-6, 5-7, 7-5. Sundstrom defeated Andreas Maurer of West Germany, 7-5, 7-5, and Nystrom eliminated Jimmy Brown, 6-1, 6-4.
Also advancing were two Argentines, Guillermo Vilas and Jose-Luis Clerc, along with Andres Gomez of Ecuador and Miloslav Mecir of Czechoslovakia.
Vilas, who plays Wilander in the quarterfinals, defeated Francesco Cancellotti of Italy, 7-5, 6-1. Clerc eliminated countryman Roberto Arguello, 6-3, 6-2, and now meets Gunnarsson.
Sundstrom's quarterfinal rival is Gomez, who defeated Fernando Luna of Spain, 6-3, 6-2. Mecir, who beat countryman Libor Pimek, 6-1, 6-3, will oppose Nystrom.
The No. 1-seeded doubles team of Martina Navratilova and Elise Burgin easily advanced to the semifinals of a $150,000 tournament at Houston with a 6-0, 6-2 victory over Emiko Okagawa and Sylvia Schenck.
The No. 2-seeded team of Manuela Maleeva and Helena Sukova also moved into the semifinals by defeating Sandy Collins and Mary Lou Piatek, 6-4, 6-4.
In the only afternoon singles match of the day, Piatek reached the quarterfinals by defeating Okagawa, 6-4, 6-7, 6-0.
Navratilova and Burgin needed just 41 minutes to win their match. In the second set, Okagawa and Schenck tied the score at 2-2, but the favorites won the next four games to end the match.
Maleeva of Bulgaria and Sukova of Czechoslovakia had a tougher time. They were pressed at 5-4 in the first set before winning the 10th game. The teams were tied 4-4 in the second set but Maleeva and Sukova won the next two games.