Top-seeded Stefan Edberg and second-seeded Boris Becker were upset Thursday in the $1.7-million German Open at Hamburg.
Becker was beaten by fellow German Bernd Karbacher, 6-3, 6-4, as his troubles on clay continue.
When Becker beat another German, Carl-Uwe Steeb, in two sets on Wednesday, he said his clay-court crisis was over. Becker, ranked No. 4 in the world, has won only two matches in his last four tournaments on clay.
Becker seemed to take his loss in stride. "It's not news when I lose on clay," he said. "My problems on clay are well-known and other players know that I am not so good on clay."
Edberg lost to Emilio Sanchez of Spain, 4-6, 7-6 (7-5), 6-4. Sixth-seeded Michael Stich, last year's runner-up, reached the quarterfinals by beating Thomas Muster of Austria, 7-6 (7-4), 2-6, 6-1.
No. 7-seeded Richard Krajicek of the Netherlands advanced by beating Jaime Oncins of Brazil, 6-2, 6-4. Horacio de la Pena of Argentina, a qualifier, defeated Francisco Clavet of Spain, 6-2, 6-4.
Marc Goellner of Germany, who had upset fifth-seeded Michael Chang in the previous round, also was eliminated, losing to Andrei Chesnokov of Russia, 6-1, 4-6, 6-2.
Magnus Gustafsson of Sweden upset eighth-seeded Karel Novacek of the Czech Republic, 2-6, 6-3, 7-6 (7-2).
Martina Navratilova, playing her first tournament after a 10-week layoff, defeated Japan's Naoko Sawamatsu, 6-4, 6-4, to reach the quarterfinals of the Italian Open at Rome.
The two-hour match was interrupted for three hours by rain.
Jennifer Capriati also advanced, beating South Africa's Amanda Coetzer, 7-6 (8-6), 4-6, 6-2, in a baseline battle, and No. 6-seeded Conchita Martinez of Spain defeated Nathalie Herreman of France, 6-1, 6-0.
Top-seeded Arantxa Sanchez Vicario beat Brenda Schultz of the Netherlands, 6-4, 6-0, and 16-year-old qualifier Francesca Bentivoglio of Italy ousted 15th-seeded Natalia Zvereva, 7-5, 5-7, 6-4, in a night match that took nearly three hours.
Bentivoglio, ranked 329th in the world, earlier defeated seventh-seeded Jana Novotna after gaining entry to the tournament through the qualifying round.
Navratilova's layoff, due to a tender right ankle, was the longest of her 18-year career. She was far from sharp against the 16th-seeded Sawamatsu.
Navratilova entered the Italian Open to get ready for another assault on Wimbledon, which she has won nine times. She is skipping the French Open, the only Grand Slam event played on clay, but plans to enter two warm-ups in England on grass.
Bryan Shelton fought off two match points and rallied to beat eighth-seeded Derrick Rostagno, 1-6, 7-6 (13-11), 6-2, at the USTA Men's Clay Court of Tampa, and Wally Masur of Australia beat Brian Dunn, 7-5, 1-6, 6-4. The night matches were rained out.