Martin Strelba of Czechoslovakia, ranked 90th in the world, upset Wimbledon champion Stefan Edberg of Sweden, 6-3, 6-3, in the $205,000 Bavarian Open tennis tournament at Munich, West Germany, Saturday.
In today's final, Strelba will meet Andrei Chesnokov, who ousted Soviet countryman, Alexander Volkov, 6-2, 7-5.
Strelba's previous best performance came last year when he reached the semifinals of a Grand Prix tournament at Prague, Czechoslovakia.
Edberg, ranked fourth in the world, could not match Strelba's strong clay-court game.
"I didn't believe before that I could beat any of the top 10-ranked players in the world," said Strelba, 22. "Now I know I can beat anyone.
"My passing shots were incredible today, but my first serve was also strong."
Top-seeded Ivan Lendl continued to dominate Brad Gilbert, and defending champion Andre Agassi overcame a strained back to beat Aaron Krickstein in the quarterfinals of the Tournament of Champions in New York.
Lendl's 6-0, 6-1 victory was his 15th without a loss over Gilbert, and Agassi rallied in the final set to eliminate Krickstein, 6-1, 2-6, 6-3.
In the other quarterfinal matches, eighth-seeded Michael Chang beat No. 15 Marcelo Filippini of Uruguay, 6-4, 6-7 (7-2), 6-2, and Jaime Yzaga of Peruo downed Diego Perez of Uruguay, 6-7 (7-4), 6-0, 6-2.
Lendl will play Agassi, and Chang will meet Yzaga in the semifinals.
Lendl needed only 58 minutes to eliminate Gilbert, ranked 17th in the world.
Krickstein broke Agassi at love in the opening game of the third set and then held for a 2-0 lead. But Agassi won the next five games despite a stiff back that began bothering him early in the second set.
"After he got up, 2-0, in the third set, he probably started thinking a little bit," Agassi said. "He stopped hitting winners, and I got the momentum back."
Chang, 17, of Placentia, who is ranked 22nd in the world, blew a 5-2 lead in the second set but came back to beat Filippini.
"I have to learn to keep concentrating when I'm up, 5-2," Chang said. "The guys are too good and will keep fighting to the last point. I have to get that into my head."
Top-seeded Steffi Graf of West Germany and Jana Novotna of Czechoslovakia won their semifinal matches in the $200,000 Virginia Slims at Hamburg, West Germany.
Graf, the top-ranked woman player in the world, struggled in the first set after blowing a 5-1 lead but rallied to win seven consecutive games to crush Bettina Fulco of Argentina, 6-4, 6-0, in 61 minutes.
Novotna overcame an ankle injury to beat fourth-seeded Arantxa Sanchez of Spain, 7-6 (7-1), 3-6, 6-1, and advance to today's final.
Novotna's injury, however, could force her to default the final, she said.
"I'll have to have it X-rayed in the hospital and then decide if I can play," Novotna said. "I can only hope but at the moment I really don't know if I'll be able to play."
Novotna, seeded sixth, twisted her ankle at 5-5 in the first set when she raced to the net. After a five-minute break, Novotna returned and eventually won in a tiebreaker.
With the injury restricting Novotna's movements, Sanchez built a 5-0 lead in the second set. Novotna won the next three games but Sanchez held her serve to win, 6-3.
Novotna rallied in the decisive set, gained two consecutive breaks and opened a 5-1 lead before winning.
Fulco rallied in the first set by returning lobs on the slow clay that frustrated Graf.
But Graf rallied to break Fulco in the 10th game and win, 6-4. Graf swept through the second set without losing a game.
Audra Keller of Memphis, Tenn., defeated Angelica Gavaldon of Coronado to win the 18-and-under singles title in the Seventeen Magazine Tennis Tournament of Champions at the Marguerite Recreation Center in Mission Viejo.
The top-seeded Keller won, 6-3, 6-2.
In the 16-and-under competition, top-seeded Keri Phebus of Newport Beach, defeated unseeded Kim Shasby of North Liberty, Iowa, 2-6, 6-2, 6-2.
In the 14s, No. 1-seeded Nicole London of Rolling Hills Estates defeated second-seeded Chanda Rubin of Lafayette, La., 6-4, 4-6, 6-2.