Number four seed Nikolay Davydenko of Russia beat Italy's Andreas Seppi 6-1, 6-2 in the second round of the Hamburg Masters on Wednesday.
The Ukrainian-born world number six, a semi-finalist here and at the French Open in 2005, was forced to retire from his third-round match at last week's Rome Masters with a leg injury.
But he came through easily on Wednesday against the tall Italian in windy and overcast conditions on the red clay at the Am Rothenbaum.
The tournament has its weakest field in years after Roland Garros champion Rafael Nadal and last year's Hamburg winner Roger Federer pulled out, citing fatigue after their five-set Rome final on Sunday lasted more than five hours.
Argentina's David Nalbandian, Andy Roddick of the US and Australia's Lleyton Hewitt had already withdrawn and only five of the world's top 10 are taking part.
Croatia's Ivan Ljubicic, number five in the world and the third seed, is now the highest-ranked player in the event and plays Argentina's Jose Acasuso on centre court later on Wednesday.
Former French Open champion Gaston Gaudio of Argentina, the number six seed, takes on Frenchman Gilles Simon and seventh seed Fernando Gonzalez of Chile plays Slovak Dominik Hrbaty.
British teenager Andy Murray, who scored an impressive win over Rome semi-finalist Gael Monfils of France on Tuesday, faces number five seeded American James Blake.