US Open: Serena Williams, Victoria Azarenka and Novak Djokovic feature on day nine
The three highest seeds left in the US Open all feature in a bumper day of women's action, while Andy Murray also plays.
Last Updated: 03/09/13 9:25pm
Murray takes on Denis Istomin on Arthur Ashe Stadium during the night session, but before that clash three high-profile women's matches take centre stage.
A long rain delay on Monday meant that the clash between last year's finalist Victoria Azarenka and former world No 1 Ana Ivanovic has been carried over and is first on Arthur Ashe today.
The big-hitting Azarenka will be a big favourite to advance to the last four with Ivanovic, who edged past home hope Christina McHale last time out, looking to reach only her second grand slam quarter-final in five years.
Theirs is the only outstanding women's fourth round match, with the two quarter-finals in the top half of the draw also taking place on Tuesday.
Fifth seed Li Na faces Ekaterina Makarova in the second match on Flushing Meadows' main court, the Russian a dangerous opponent having knocked out former Wimbledon finalist Agnieszka Radwanska in the previous round.
The winner of that match will face either defending champion Serena Williams or Spanish outsider Carla Suarez Navarro in the last four.
Williams is first up in the night session and although her Spanish opponent is in a rich vein of form, anything other than a convincing win for the top seed would be a huge surprise.
Men's No 1 seed Novak Djokovic is also in action, the Serb slated to be third on Arthur Ashe against Spain's Marcel Granollers, whose run to round four means Djokovic has not yet faced a seeded opponent.
That streak will continue into the semi-finals if Lleyton Hewitt is able to roll back the years again when he faces 21st seed Mikhail Youzhny on Louis Armstrong.
The remaining men's match could well be the most competitive of the day as ninth seed Stanislas Wawrinka faces fifth-ranked Tomas Berdych for the right to face either Murray or Istomin in the last eight.
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