World No. 2 Rafael Nadal, shown here in action earlier this year, collected a second-round win Wednesday at the Masters Series tournament in Germany.

HAMBURG, Germany, May 14 (UPI) -- Top-seeded Roger Federer and No. 2 Rafael Nadal collected straight-set wins Wednesday in second-round action at the $2.95 million Masters Series Hamburg.

Federer, ranked No. 1 in the world, dispatched Jarkko Nieminen 6-1, 6-3, and Nadal, the No. 2 player in the world, took out Potito Starace 6-4, 7-6 (8-6). Federer and Nadal last year met in the finals of this French Open tuneup, with Federer winning.

No. 7-seeded James Blake fell 4-6, 6-3, 6-3 to Janko Tipsarevic and ninth-seeded Tomas Berdych lost 7-5, 6-4 to Marat Safin in the day's biggest upsets.

A pair of midrange seeds were also ousted Wednesday. Ivo Karlovic saved a match point and then put away 13th-seeded Tommy Robredo 3-6, 6-2, 7-6 (7-3) and Robin Soderling beat No. 14 Jo-Wilfried Tsonga 6-2, 7-5.

Other second-round results saw No. 11-seeded Carlos Moya beating Olivier Rochus 7-5, 6-3; No. 12 Juan Monaco stopping Simone Bolelli 6-2, 6-1; and No. 15 Andy Murray topping Gilles Simon 6-3, 6-3. Crowd favorite Nicolas Kiefer downed Stanislas Wawrinka 7-5, 7-5 and Albert Montanes dismissed Jose Acasuso 7-6 (7-3), 6-3.