Nikolay Davydenko defeated last year's runner-up Marin Cilic of Croatia 7-5, 6-3 on Friday to reach the semifinals of the BMW Open.
Davydenko, who is seeded seventh, was runner-up in Munich on 2004. Cilic had won three of his four previous matches against the Russian, but has now lost the last two.
Davydenko will next play Radomir Stepanek of the Czech Republic, who beat 2007 Munich champion Philipp Kohlschreiber of Germany, 6-4, 6-0.
Philipp Petzschner of Germany edged Potito Starace of Italy 7-6 (3), 7-6 (6) to set up a semifinal against another German, fifth-seeded Florian Mayer, who overcame Bulgarian teenager Gregori Dimitrov 7-6 (4), 3-6, 6-4.
The 69th-ranked Dimitrov turns 20 next month and is the only teenager in the top 100. It was his first quarterfinal appearance on the tour.
Despite hitting eight aces the Bulgarian could not match the steady play of Mayer, who had never won a match in Munich in three previous visits and who has reached his third semifinal of the year.
The last time two German players were in the Munich semifinals was in 1994, when Michael Stich and Bernd Karbacher reached the last four. The last German winner was Kohlschreiber.
