Venue: Flushing Meadows, New York Dates: 31 August-13 September
Coverage: Live radio and text commentary on every Andy Murray match plus selected matches
Serena Williams saw off a significant threat to her Grand Slam hopes with victory over 19th seed Madison Keys at the US Open.
Williams, the world number one, beat her fellow American 6-3 6-3 to set up a quarter-final against her sister Venus.
Serena Williams, 33, is now three wins from competing the first calendar Grand Slam since Steffi Graf in 1988.
The next player in her path is 35-year-old Venus Williams, who beat Estonia's Annett Kontaveit 6-2 6-1.