Elena Rybakina became world number one for the first time last month after winning the US Open. (EPA Images pic)TOKYO: Elena Rybakina withdrew from the Pan Pacific Open in Tokyo with a neck injury on Friday, a day after she secured the year-end world number one ranking.

The Moscow-born Kazakh was due to face Canada's Leylah Fernandez in the quarter-finals, but instead she came onto the court to address the crowd and sign autographs.

She said she would return for next month's WTA Finals in Indian Wells.

"I just wanted to say thank you so much for coming today, but unfortunately I won't be able to play," said the 27-year-old.