Stuttgart - Fabio Fognini has opened the defence of his Mercedes Cup title by defeating Andrey Golubev 6-4, 6-4 to advance to the quarter-finals on Thursday.
The top-seeded Italian will next face the seventh-seeded Santiago Giraldo of Colombia, who defeated qualifier Philipp Davydenko of Russia 6-1, 6-7 (5), 6-3.
No. 2 seed Mikhail Youzhny eased past Argentina's Leonardo Mayer 6-1, 6-1.
The Russian, who won the tournament in 2002, next plays the eighth-seeded Argentine Federico Delbonis, who defeated Germany's Benjamin Becker 6-7 (6), 6-4, 6-4.
The third-seeded Roberto Bautista Agut of Spain beat Louk Sorensen of Ireland 6-3, 1-6, 6-1, for a quarterfinal against compatriot Guillermo Garcia-Lopez. The No. 6 seed earlier defeated Swiss qualifier Yann Marti 7-6 (13), 7-5.
Another Spaniard, the fourth-seeded Feliciano Lopez, defeated countryman Daniel Gimeno-Traver 6-7 (3), 6-2, 6-3 and will play Lukas Rosol of the Czech Republic in the last eight.
Home favourite Philipp Kohlschreiber won't be there. The German defeated compatriot Jan-Lennard Struff 6-4, 6-3 in their rain-postponed first-round match, but later lost 7-5, 7-6 (5) to Rosol in the second round.
Results from the fourth day of the Stuttgart ATP tournament on Thursday (x denotes seeding):
Fabio Fognini (ITA x1) bt Andrey Golubev (KAZ) 6-4, 6-4
Santiago Giraldo (COL) bt Philip Davydenko (RUS) 6-1, 6-7 (5/7), 6-3
Roberto Bautista (ESP x3) bt Louk Sorensen (EIR) 6-3, 1-6, 6-1
Guillermo Garca-Lpez (ESP x6) bt Yann Marti (SUI) 7-6 (15/13), 7-5
Luks Rosol (CZE) bt Philipp Kohlschreiber (GER x5) 7-5, 7-6 (7/5)
Feliciano Lopez (ESP x4) bt Daniel Gimeno (ESP) 6-7 (3/7), 6-2, 6-3
Federico Del Bonis (ARG x8) bt Benjamin Becker (GER) 6-7 (6/8), 6-4, 6-4
Mikhail Youzhny (RUS x2) bt Leonardo Mayer (ARG) 6-1, 6-1
Philipp Kohlschreiber (GER x5) bt Jan-Lennard Struff (GER) 6-4, 6-3