Stuttgart - Qualifier Pavol Cervenak of Slovakia upset eighth-seeded Tommy Haas of Germany 6-4, 6-4 on Thursday to reach the quarter-finals of the Mercedes Cup.
Third-seeded Bernard Tomic of Australia was also eliminated, losing to Thomaz Bellucci of Brazil. Bellucci trailed 4-1 but rallied to win 7-6 (8/6), 6-3.
Cervenak broke Haas in the opening game and saved seven break points in the first set.
Second-seeded Juan Monaco of Argentina breezed past Tobias Kamke of Germany 6-2, 6-3.
Results from the fourth day of the ATP tournament on Thursday (x denotes seeding):
Thomaz Belluci (BRA) bt Bernard Tomic (AUS x3) 7-6 (8/6), 6-3
Cedrik-Marcel Stebe (GER) bt Jrmy Chardy (FRA) 4-6, 7-6 (10/8), 6-3
Pavol Cervenk (SVK) bt Tommy Haas (GER x8) 6-4, 6-4
Juan Monaco (ARG x2) bt Tobias Kamke (GER) 6-2, 6-3