Naomi Osaka's latest reign as world number one looks to be a short one, with Ashleigh Barty close to dethroning the Japanese.
Naomi Osaka and Ashleigh Barty won through as Madison Keys overcame Simona Halep at the Western & Southern Open.
It was a good day for the seeds at the Western & Southern Open as Naomi Osaka, Simona Halep and Ashleigh Barty advanced.
Losing to Serena Williams gave Naomi Osaka an experience she had been waiting her whole career for at the Rogers Cup in Toronto on Friday.
As Simona Halep's title defence came to an end at the Rogers Cup, Serena Williams was in impressive form.
In their first meeting since last year's controversial US Open final, Serena Williams was too good for Naomi Osaka.
Serena Williams and second seed Naomi Osaka will do battle for a spot in the Rogers Cup semi-finals.
Serena Williams and Naomi Osaka cruised as the seeds dominated at the Rogers Cup.
In a revealing Twitter post, Naomi Osaka said: "I probably haven't had fun playing tennis since Australia."
Naomi Osaka encouraged Serena Williams to 'continue trailblazing' after the US Open flashpoint that overshadowed her maiden grand slam win.