Rybakina withdraws from Pan Pacific semifinal, WTA Finals berth

Elena Rybakina withdrew from the Pan Pacific Open semifinal in Tokyo on Saturday, citing back problems, hours after beating Victoria Mboko to clinch the final spot in next month's WTA Finals in Riyadh. The 2022 Wimbledon champion had been scheduled to face Linda Noskova but pulled out before the match, saying she could not play at full strength.

Rybakina secured qualification for the season-ending eight-player event with a 6-3, 7-6 (4) quarterfinal victory over 19-year-old Mboko on Friday, following an earlier 6-4, 6-3 win over Leylah Fernandez. The Tokyo results completed a six-match winning streak that included last week’s Ningbo Open title and lifted Rybakina into the final qualifying position ahead of Mirra Andreeva, who did not play in Tokyo. With the points from Tokyo, Rybakina is set to move up to world No. 6 when the rankings are updated.

“I’m very sorry I can’t play today,” Rybakina said in a statement. “I have been having problems with my back this week and can’t play 100. I am disappointed that my fans will not see me today but I hope to see you next year.” She had also described her win over Mboko as hard-fought, saying she was “happy that today I managed to win in...