Big-serving Lukas Rosol 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 stunned Rafael Nadal in the second round of Wimbledon earlier this month. 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.
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.