Updated

Florian Mayer was one of three German winners Monday at the $1.44 million German Open Tennis Championships.

Mayer mauled one-time world No. 3 Russian Nikolay Davydenko 6-1, 6-3 on the red clay at Am Rothenbaum.

Meanwhile, German Daniel Brands handled Italian Paolo Lorenzi 7-5, 6-3 and the host nation's Tobias Kamke leveled Czech slugger Lukas Rosol 6-3, 6-0 in first-round action.

Also on Day 1, Czech Jan Hajek whipped Polish fellow qualifier Lukasz Kubot 6-3, 6-2; rising Spaniard Roberto Bautista Agut beat German wild card Alexander Zverev 6-3, 6-2; Russian Dmitry Tursunov overcame Spaniard Pablo Andujar 6-7 (5-7), 7-6 (7-4), 6-2; and Spain's Albert Montanes topped Frenchman Paul-Henri Mathieu 6-4, 6-4.

Argentine Juan Monaco downed German favorite Tommy Haas in last year's Hamburg finale. Monaco is this week's fifth seed, while Haas is No. 2 in the draw.

This week's top seed is four-time Hamburg champion Roger Federer, who will open his stay against Brands.

Sixteen seeds received opening-round byes.

The 2013 Hamburg titlist will earn $328,000.