Davydenko, seeded fourth, drilled Ivan Ljubicic, 6-4, 6-1, and Ferrer, seeded fifth, defeated Ivo Minar, 6-3, 6-3, to make the tournament round of 16. Ferrer next goes against Fernando Verdasco, who pasted Michael Llodra, 6-2, 6-0, in his second-round match.
In first-round play, 11th-seeded Carlos Moya rallied for a 3-6, 6-4, 7-6 (9-7) victory over Julien Benneteau. Also Tuesday, Robin Soderling and Janko Tipsarevic won three-set matches while Jose Acasuso and Potito Starace advanced when their opponents retired.
Acasuso was ahead 5-2 when Kristof Vliegen was forced to stop because of a back problem and Acasuso was up 6-3, 4-2 when Luis Horna reported a calf injury.
Starace draws world No. 2 Rafael Nadal on Wednesday. Also in action Wednesday is top-seeded Roger Federer, who beat Nadal in the finals for the 2007 Hamburg title. It was Federer's fourth Hamburg championship in six years.