Big-serving Lukas Rosol, who stunned Rafael Nadal at Wimbledon, beat fifth-seeded Robin Haase of the Netherlands 6-4, 7-5 on Tuesday to advance to the second round of the Mercedes Cup.
Rosol beat the Spanish star in the second round at the All England Club earlier this month, but despite that win, the Czech actually dropped three places to No. 103 in the ATP rankings.
Rosol served 12 aces and won 91 percent of his first-serve points against Haase.
Germany's Tommy Haas, the eighth seed, rallied to beat Igor Andreev of Russia 4-6, 6-2, 6-2, and countryman Cedrik-Marcel Stebe upset seventh-seeded Lubosz Kubot of Poland 6-2, 0-6, 6-3. Kubot served 10 double-faults.
Also moving into the second round were Bjorn Phau of Germany, Thomaz Bellucci of Brazil, Benoit Paire of France, Tobias Kamke of Germany, Pavol Cervenak of Slovakia and Jeremy Chardy of France.