Serena Williams admits sister Venus is 'the only player I don't want to play'

Serena Williams admits her sister Venus is the one player she fears at the US Open.

The most famous siblings in tennis will meet for the 27th time in the quarter-finals at Flushing Meadows after Serena ousted fellow American Madison Keys 6-3 6-3 and Venus thrashed Estonian qualifier Anett Kontaveit 6-2 6-1.