US Open 2015: Serena Williams, Venus to meet in quarter-finals

Serena Williams defeated her fellow American Madison Keys 6-3, 6-3 on Sunday night to set up a quarter-final against her sister Venus.

Serena now faces Venus, at 35 in her 35th Grand Slam last eight after she dismissed qualifier Anett Kontaveit 6-2, 6-1.

The 33-year-old world number one is now three wins from competing the first calendar Grand Slam since Steffi Graf in 1988.