New York, Sep 4 (IANS) Following are the results of day nine of competitions at the US Open tennis tournament here.

Men's singles Fourth round (prefix number denotes seeding):

1-Novak Djokovic (SER), bt Marcel Granollers (ESP)- 6-3, 6-0, 6-0
21-Mikhail Youzhny (RUS), bt Lleyton Hewitt (AUS)- 6-3, 3-6, 6-7 (3-7), 6-4, 7-5
9-Stanislas Wawrinka (SUI), bt 5-Tomas Berdych (CZE)- 3-6, 6-1, 7-6 (8-6), 6-2
3-Andy Murray (GBR), bt Denis Istomin (UZB)- 6-7 (5-7), 6-1, 6-4, 6-4

Women's singles Quarter-finals:

1-Serena Williams (USA), bt 18-Carla Suarez Navarro (ESP)- 6-0, 6-0
5-Li Na (CHN), bt 24-Ekaterina Makarova (RUS)- 6-4, 6-7 (5-7), 6-2

Fourth round:

2-Victoria Azarenka (BLR), bt 13-Ana Ivanovic (SER)- 4-6, 6-3, 6-4

Men's doubles Quarter-finals:

4-Leander Paes/Radek Stepanek (IND/CZE), bt 5-Aisam-ul-Haq Qureshi/Jean-Julien Rojer (PAK/NED)- 6-1, 6-7 (3-7), 6-4
2-Alexander Peya/Bruno Soares (AUT/BRA), bt Jamie Murray/John Peers, (GBR/AUS)- 6-4, 6-7 (4-7), 6-4

Women's doubles Quarter-finals:

2-Ekaterina Makarova/Elena Vesnina, (RUS), bt 13-Cara Black/Marina Erakovic, (ZIM/NZL)- 5-7, 6-2, 6-4

Mixed doubles Quarter-finals:

5-Anabel Medina Garrigues/Bruno Soares (ESP/BRA), bt Lucie Hradecka/Frantisek Cermak, (CZE)- 6-4, 6-7 (3-7), 13-11
Abigail Spears/Santiago Gonzalez (USA/MEX), bt 8-Liezel Huber/Marcelo Melo, (USA/BRA)- 2-6, 6-1, 11-9
Kristina Mladenovic/Daniel Nestor (FRA/CAN), bt Chan Hao-Ching/Martin Emmerich, (TPE/GER)- 7-6 (7-5), 6-3