Five facts for Wednesday, day 10 at the US Open:
- World number one Novak Djokovic takes on eighth-seeded Andy Murray in a blockbuster quarter-final. Djokovic leads their career head-to-head 12-8, and has won three of their five Grand Slam encounters. Both of Murray`s wins came in Grand Slam finals, including a five-set triumph at Flushing meadows in 2012, when they tied the record for longest US Open final at four hours, 54 minutes.
- Djokovic is attempting to become the seventh player in the Open Era with at least 50 US Open match wins. The 27-year-old Serb, who is one week younger than Murray, is trying to join Roger Federer and Ivan Lendl with eight consecutive US Open semi-final appearances, trailing only Jimmy Connors` Open Era record of 12.
- Australian Open champion Stan Wawrinka, seeded third, brings a 2-0 head-to-head edge against Japanese 10th seed Kei Nishikori. Wawrinka, making his seventh career quarter-final appearance in a Grand Slam, is vying to reach the US Open semi-finals for the second straight year.
- Nishikori is playing in his second Grand Slam quarter-final having also reached the last eight at the 2012 Australian Open. He is trying to become the first Japanese man to reach a Grand Slam semi-final since Jiro Satoh at Wimbledon in 1933.
- Five-time champion Serena Williams takes on Flavia Pennetta for a semi-final berth. Williams, who hadn`t made it past the fourth round at any of the year`s first three majors, has won all five prior encounters with the Italian. In the day`s other women`s quarter-final Victoria Azarenka -- runner-up to Williams the past two years -- faces Russian Ekaterina Makarova, who is winless in four previous Grand Slam quarter-final appearances, the most recent at Wimbledon this year.