Big-serving Croat Ivo Karlovic continued his good run of form to dump former winner Marat Safin out of the Madrid Masters 6-3, 6-4 in the first round on Tuesday.
Karlovic, who won his third title of the season in Stockholm on Sunday, wrapped up the victory with his 17th ace of the match, overpowering the 2004 winner in 58 minutes.
The 28-year-old, at a career high 24 in the ATP rankings, earned a second round encounter with another Russian, fourth-seed Nikolay Davydenko.
Earlier, Spanish debutant Nicolas Almagro beat Fabrice Santoro 6-4, 6-4 to meet fifth seed Fernando Gonzalez in the second round, while Germany's Nicolas Kiefer overcame Stanilas Wawrinka 7-5, 6-3. He will play Russian 16th-seed Mikhail Youzhny next.
Later, top seed and defending champion Roger Federer takes on American qualifier Robby Ginepri in the second round, and Britain's Andy Murray plays Argentine Juan Ignacio Chela.