The top-seeded Australian outlasted German wild card Markus Hantschk, 6-1, 4-6, 6-4, at this claycourt event.
The world No. 1, Hewitt has been tested previously by Hantschk. In the second round of the 2000 French Open, Hewitt rallied twice to escape with a win. Hewitt awaits a tough second-round meeting with France's Arnaud Clement.
The second-seeded Moya continued his strong claycourt season with a 6-3, 5-7, 6-3 win over qualifier Scott Draper of Australia. Moya improved to 22-3 on clay in 2003 and set up a second-round encounter with another qualifier, fellow countryman Rafael Nadal.
In a rematch of their semifinal clash here a year ago, No. 3 Federer rolled to a 6-3, 6-3 win over Max Mirnyi of Belarus. Federer also won in straight sets against Mirnyi at the Rothenbaum en route to the 2002 Hamburg title. But the 25-year-old from Minsk had taken their previous two meetings in the round of 16 at the 2002 U.S. Open and the semifinals of the 2003 Rotterdam event.
Federer improved to 4-2 lifetime against Mirnyi and advanced to meet Armenian qualifier Sargis Sargsian, who rallied past Slovakia's Dominik Hrbaty, 6-7 (4-7), 6-4, 6-4.
Roddick, the fourth seed, reached the second round with a 6-4, 6-4 win over Ivan Ljubicic of Croatia. Roddick, who made the third round in his Hamburg debut last year, next faces Argentina's Agustin Calleri.
The fifth-seeded Costa won his third straight meet with local favorite Nicolas Kiefer, 6-4, 6-4. The 1998 Hamburg titlist, Costa faces a second-round encounter with Belgian Olivier Rochus.
Czech Jiri Novak was the highest seed to fall on Tuesday. Russian Mikhail Youzhny eliminated the sixth seed, 6-1, 6-4. Youzhny's second-round foe is Slovakian lucky loser Karol Beck, who outlasted harding-serving Australian Wayne Arthurs, 6-4, 3-6, 6-3.
In another upset Tuesday, Belgium's Xavier Malisse knocked off two-time French Open runner-up and 13th seed Alex Corretja, 7-6 (7-3), 4-6, 6-3. Malisse's next opponent is Australia's Mark Philippoussis, who defeated Dutchman Raemon Sluiter, 6-4, 7-5.
No. 8 David Nalbandian of Argentina, No. 9 RainerSchuettler of Germany and No. 10 Sebastien Grosjean of France each posted straight-sets wins in the first round.
Chilean Fernando Gonzalez, the 15th seed, French qualifier Anthony Dupuis and Spaniard Felix Mantilla also earned first-round wins.
This French Open tune-up awards the winner $462,313.