World number one Serena Williams produced a perfect blend of force and aggression as she outclassed compatriot Madison Keys in straight sets to reach the quarter-finals of the US Open.
Serena overcame hard-hitting Keys 6-3, 6-3 to set up a last-eight encounter against her sister Venus at Flushing Meadows.
The 21-time Grand Slam champion shrugged off signs of fallibility with a much better performance and supreme shot selection.
With the win, Serena stands only three wins away from securing the first calendar Grand Slam since Steffi Graf in 1988.
