Updated

The ATP World Tour has shifted from clay to grass this week, and Germany's Florian Mayer was among the Day-1 winners at the $900,000 Gerry Weber Open.

The eighth-seeded Mayer mauled Austrian qualifier Martin Fischer 6-2, 6-2 at Gerry Weber Stadium.

Also on Monday, Russian veteran Mikhail Youzhny routed Spaniard Daniel Gimeno- Traver 6-1, 6-2, German wild card Mischa Zverev overcame Belgian David Goffin 1-6, 6-4, 7-5, and Czech qualifier Jan Hernych humbled German Daniel Brands 6-4, 6-2. Youzhny's second-round opponent will be fourth-seeded rising Japanese Kei Nishikori.

This week's top seeds are five-time Gerry Weber champion Roger Federer, French star Richard Gasquet and long-time German favorite and defending champion Tommy Haas, who stunned Federer in last year's grass-court Halle finale. Haas also titled here back in 2009.

The seven-time and reigning Wimbledon titlist Federer has appeared in the Halle final on seven occasions.

This week's winner will earn $163,000.