Rome - Roger Federer eased past Gilles Simon 6-1, 6-2 on Thursday to reach the Rome Masters quarter-finals.
The second seed will face Poland's Jerzy Janowicz, who beat ninth-seed Richard Gasquet, for a place in the semi-finals.
Results on the fifth day of the ATP Rome Masters/WTA Rome Open on Thursday (x denotes seeding).
Men:
Novak Djokovic (SRB x1) bt Alexandr Dolgopolov (UKR) 6-1, 6-4
Tomas Berdych (CZE x6) bt Kevin Anderson (RSA) 7-5, 6-2
Rafael Nadal (ESP x5) bt Ernests Gulbis (LAT) 1-6, 7-5, 6-4
Benoit Paire (FRA) bt Juan Martin Del Potro (ARG x7) 6-4, 7-6 (7/3)
David Ferrer (ESP x4) bt Philipp Kohlschreiber (GER) - walkover
Marcel Granollers (ESP) bt Jeremy Chardy (FRA) 6-4, 1-6, 7-5
Jerzy Janowicz (POL) bt Richard Gasquet (FRA x9) 3-6, 7-6 (7/2), 6-4
Roger Federer (SUI x2) bt Gilles Simon (FRA) 6-1, 6-2
Women:
Serena Williams (USA x1) bt Dominika Cibulkova (SVK x14) 6-0, 6-1
Carla Suarez (ESP) bt Lourdes Dominguez (ESP) 6-2, 6-3
Simona Halep (ROM) bt Roberta Vinci (ITA x13) 6-4, 6-2
Jelena Jankovic (SRB) bt Li Na (CHN x5) 7-6 (7/2), 7-5
Victoria Azarenka (BLR x3) bt Ayumi Morita (JPN) 6-1, 2-0 - retired
Sara Errani (ITA x7) bt Maria Kirilenko (RUS x12) 6-3, 2-0 - retired
Samantha Stosur (AUS x9) bt Petra Kvitova (CZE x8) 7-5, 2-6, 6-1
Maria Sharapova (RUS x2) bt Sloane Stephens (USA x16) 6-2, 6-1