Naomi Osaka Loses World No.1 Ranking

Naomi Osaka loses world No.1 ranking

Japanese tennis star Naomi Osaka has lost her world-number-one ranking after falling in the second round of a tournament in Britain last week.

Australia's Ashleigh Barty took the title on Sunday for her third tournament victory this year.

Barty replaces Osaka in the latest rankings, announced by the Women's Tennis Association on Monday.

Barty became the world number two after winning the French Open earlier this month.

Osaka was the top-ranked women's tennis player for five months, since winning the Australian Open in January.

That was her second straight Grand Slam title, following last year's US Open.

But Osaka has failed to win any WTA tour events since then.