Serena advances to quarters

Cincinnati - Top seed Serena Williams stayed the course at the ATP-WTA Cincinnati Masters on Thursday, pounding out a 6-4, 6-1 defeat of Mona Barthel.

The American beat her 32nd-ranked German in dominating style in a night game to reach the quarter-finals of the hard-court tournament.

Williams is playing the event for the fifth time, with her best showing to date being a semi-final berth in 2006.

Results on Thursday from the ATP and WTA Western and Southern Open (x denotes seed):

Men

Third round

Novak Djokovic (SRB x1) bt David Goffin (BEL) 6-2, 6-0

Dmitry Tursunov (RUS) bt David Ferrer (ESP x3) 6-2, 6-4

Juan Martin Del Potro (ARG x7) bt Feliciano Lopez (ESP) 6-4, 1-6, 6-4

Roger Federer (SUI x5) bt Tommy Haas (GER x11) 1-6, 7-5, 6-3

John Isner (USA) bt Milos Raonic (CAN x12) 7-6 (7/5), 6-4

Andy Murray (GBR x2) bt Julien Benneteau (FRA) 6-2, 6-2

Rafael Nadal (ESP x4) bt Grigor Dimitrov (BUL) 6-2, 5-7, 6-2

Tomas Berdych (CZE x6) bt Tommy Robredo (ESP) 6-3, 6-0

Women

Third round

Victoria Azarenka (BLR x2) bt Magdalena Rybarikova (SVK) 6-3, 6-4

Roberta Vinci (ITA x12) bt Sara Errani (ITA x6) 6-4, 6-3

Jelena Jankovic (SRB x14) bt Sloane Stephens (USA) 3-6, 7-5, 7-5

Li Na (CHN x5) bt Angelique Kerber (GER x9) 6-4, 6-4

Agnieszka Radwanska (POL x4) bt Elena Vesnina (RUS) 6-0, 6-2

Serena Williams (USA x1) bt Mona Barthel (GER) 6-4, 6-1

Simona Halep (ROM) bt Samantha Stosur (AUS x11) 6-4, 4-6, 6-2

Caroline Wozniacki (DEN x10) bt Petra Kvitova (CZE x7) 3-6, 6-2, 6-3