Chela knocked off Andrej Martin 6-3, 6-3, losing his serve just once in the process. He won nearly as many point off Martin's serve (26-30) as Martin did.
Michael Berrer defeated sixth-seeded Guillermo Garcia-Lope, the only other seeded player on Tuesday's schedule, 6-3, 4-6, 7-5. Berrer fought off eight of nine break-point situations in the final set.
Lukasz Kubot advanced to a second-round match against top-seeded Jurgen Melzer with a 6-4, 6-4 win over James Blake. Kubot converted all five of the break-point situations he forced on Blake.
Andreas Haider-Maurer, inserted into the draw when Ernest Gulbis withdrew, moved to the second round by beating Thomas Muster 6-2, 7-6 (7-5). Muster, 43, was playing in his first ATP match in 11 years. He was the No. 1-ranked player in the world in 1996.
Also Tuesday, Santiago Giraldo got past Xavier Malisse 6-4, 1-6, 6-1; Grega Zemlja topped Marsel Ilhan 4-6, 6-1, 7-5; Pablo Cuevas beat Thiemo de Bakker 7-6 (8-6), 1-6, 6-4; and Tobias Kamke, in the final match of the day, eliminated Matthias Bachinger 6-4, 6-4.