Serena Williams cruised into the Round of 16 with a facile 6-3, 6-1 win over Yaroslava Shvedova.
Agnieszka Radwanska was tested in the second set by Anastasia Pavlyuchenkova but the third seed managed to prevail 6-4, 7-6 to move into the fourth round.
World No. 1 Novak Djokovic signs his autograph for the fans after winning his second-round match against Benjamin Becker 7-6, 6-2, 6-2.
The 2009 US Open champion and sixth seed Juan Martin del Potro was stunned by the 2001 winner Lleyton Hewitt 4-6, 7-5, 6-3, 6-7, 1-6 in their second-round meeting.
Laura Robson gave Li Na a little scare but couldn't take the third-round match into a deciding set. The Chinese sealed the match in her favour 6-2, 7-5.
Sabine Lisicki, seeded 16th, was upset by the 24th-seed Ekaterina Makarova 4-6, 5-7 in the third round.
Defending champion Andy Murray was stretched to four sets by Leonardo Mayer before the Brit prevailed 7-5, 6-1, 3-6, 6-1 in the second round.