Playing his first competitive match for almost three weeks, the Swiss defending champion struggled with his first serve in front of a capacity 10,500 crowd but he still completed victory in 58 minutes.
He won 10 straight points in the first set to take a 4-2 lead and from then on Federer allowed his opponent only two more games to wrap up his 10th straight win in Rotterdam.
"My start wasn't so well because it was warmer on the court compared the training sessions I had the previous day," Federer said.
"It was also a bit difficult to see the ball in the beginning and while that might sound strange, there also is some pressure of playing a first round."
Fourth seed Richard Gasquet joined the 17-times grand slam champion in the second round with a 7-6 6-1 win over Serbia's Viktor Troicki.
Gasquet will next face Marcos Baghdatis who advanced after Benoit Paire pulled out injured. The Cypriot was leading 6-0 6-7 4-0.
Gilles Simon, seeded fifth, and Julien Benneteau completed a good day for France.
Simon eased past Italian qualifier Matteo Viola 6-3 6-1 to reach the quarter-final, while Benneteau also dropped just four games in his 6-1 6-3 win over Victor Hanescu.
ATP Rotterdam results
Grigor Dimitrov (Bulgaria) beat Nikolay Davydenko (Russia) 7-5 6-3
Julien Benneteau (France) beat Victor Hanescu (Romania) 6-1 6-3
5-Gilles Simon (France) beat Matteo Viola (Italy) 6-3 6-1
1-Roger Federer (Switzerland) beat Grega Zemlja (Slovenia) 6-3 6-1
Marcos Baghdatis (Cyprus) beat Benoit Paire (France) 6-0 6-7(3) 4-0 (Paire retired)
4-Richard Gasquet (France) beat Viktor Troicki (Serbia) 7-6(3) 6-1
Matthias Bachinger (Germany) beat 6-Andreas Seppi (Italy) 6-3 6-4
ATP San Jose results
Steve Johnson (U.S.) beat Ivo Karlovic (Croatia) 6-7(2) 6-4 7-6(6)
Michael Russell (U.S.) beat Donald Young (U.S.) 6-3 7-5
Matthew Ebden (Australia) beat Rik De Voest (South Africa) 6-2 7-5
Alejandro Falla (Colombia) beat Flavio Cipolla (Italy) 7-6(1) 7-6(10)
ATP San Paulo results
Martin Alund (Argentina) beat 4-Jeremy Chardy (France) 6-4 4-6 7-6(5)
David Nalbandian (Argentina) beat Jorge Aguilar (Chile) 7-5 5-7 6-3
Paul Capdeville (Chile) beat Horacio Zeballos (Argentina) 6-7(5) 6-0 3-0 (Zeballos retired)
Joao Souza (Brazil) beat Ruben Ramirez Hidalgo (Spain) 7-6(6) 0-0 (Ramirez Hidalgo retired)
Albert Montanes (Spain) beat Paolo Lorenzi (Italy) 6-4 6-4