Colombian qualifier Robert Farah upset defending champion Nikolay Davydenko 6-3, 6-2 in the opening round of the BMW Open in Munich, Germany, on Tuesday.
The seventh-seeded Russian, who also won the tournament in 2004, dropped serve four times.
Sixth-seeded Mikhail Youzhny of Russia, the 2010 champion, edged out Philipp Petzschner of Germany 7-5, 7-5, and eighth-seeded Marcos Baghdatis of Cyprus outlasted Tobias Kamke of Germany 6-1, 3-6, 6-3 for his first clay-court win of the season.
Baghdatis broke serve four times and saved six of eight break points to advance in a tournament he has twice been a semi-finalist.
Also advancing were Sergiy Stakhovsky of Ukraine, Ernests Gulbis of Latvia, Dustin Brown and Matthias Bachinger of Germany, Potito Starace of Italy, Tommy Haas of Germany and Marinko Matosevic of Australia.
? Serbia Open
Seeded players Lukasz Kubot of Poland, Fabio Fognini of Italy and Ryan Harrison of the US were beaten in straight sets on Tuesday in the first round of the Serbia Open.
Lukas Rosol of the Czech Republic beat the fifth-seeded Kubot 7-5, 6-2, Benoit Paire of France downed the sixth-seeded Fognini 6-1, 6-4 and Joao Souza of Brazil defeated the seventh-seeded Harrison 6-3, 6-3.
Eighth-seeded Gilles Muller downed Lukas Lacko of Slovakia 6-0, 4-6, 6-3, and Spain’s Guillermo Garcia-Lopez topped Igor Kunitsyn of Russia 7-6 (7/4), 6-7 (1/7), 6-2.
Victor Hanescu, qualifier Aljaz Bedene, Antonio Veic and Eduardo Schwank all won.
The tournament is organized by the family of top-ranked Novak Djokovic, who is sitting out the tournament after the recent death of his grandfather.