Former world number ones Lleyton Hewitt, Juan Carlos Ferrero and Marat Safin moved smoothly into the second round of the Hamburg Masters on Monday but last year's runner-up Radek Stepanek fell to Arnaud Clement.
Hewitt, playing at Hamburg for the first time since 2004 and seeded 16th, had a convincing 6-3, 6-4 victory over Agustin Calleri of Argentina in his opening match of the claycourt tournament.
Ferrero, the 15th seed, moved a step closer to a possible third-round clash with Roger Federer with a 6-1, 7-6 win over Stanislas Wawrinka of Switzerland in the first match up on centre court.
Ferrero will play Safin in the second round after the Russian beat Nicolas Massu of Chile 7-6, 6-4.
Stepanek was broken four times by Clement, a former finalist at the Australian Open and he went down 6-3, 6-7, 6-3 in two hours 20 minutes.
The Frenchman will play number eight seed James Blake of the United States in the second round.
Stepanek lost to Spaniard Tommy Robredo in straight sets in last year's final. Robredo is the sixth seed this year and, like Federer, Rafael Nadal and the rest of the top eight seeds, he has a bye into the second round.
Hewitt was recently given a clean bill of health after a frustrating series of injuries and the Australian was delighted with his first-round performance.
"A 6-3, 6-4 win over a quality claycourt opponent was very good," the Australian told reporters. "It's good to be back here after I missed a couple of years with injuries.
"I haven't given myself a goal this week. I just want to get as many matches under my belt as possible going into Paris."
The only seed to fall on the first day was Marcos Baghdatis, who was beaten 7-5, 6-3 by Germany's Philipp Kohlschreiber and even that was not much of a surprise.
Kohlschreiber, the improving 23-year-old, beat the Cypriot in straight sets in the semi-finals in Munich earlier this month before going on to win his first ATP title.
Federer, the world number one, will face Juan Monaco in the second round after the Argentine beat Dominik Hrbaty of Slovakia 6-2, 6-2 in the first round on Monday.
It will be Federer's first match since splitting from his part-time coach Tony Roche.
Nadal, who is on a 77-match winning streak on clay, will face the winner of Tuesday's first-round match between German hopeful Benjamin Becker and Oscar Hernandez of Spain.
