Los Angeles, USA: Seventh-seeded Maria Sakkari saved four match points to upset top-seeded Elina Svitolina Friday and reach the semi-finals of the WTA Silicon Valley Classic in San Jose, California.
Greece's Sakkari rallied from 1-6, 2-5 down to triumph 1-6, 7-6 (7/3), 6-3 as she remained on course to reach the final for a second straight year.
She'll face Zheng Saisai for a place in the final after the 55th-ranked Chinese player out-lasted fourth-seeded US teenager Amanda Anisimova 5-7, 7-5, 6-4.
Sakkari saved three match points in the ninth game of the second set, finally converting her fifth break point in a game that went to deuce seven times.
She saved another match point on the way to holding her own serve for 5-5 and never trailed in the second-set tiebreaker.
"I'm super-happy," Sakkari said. "I was playing very bad tennis. I was not moving, not reacting at all. I really don't know how I managed to wake up."
Second-seeded Aryna Sabalenka of Belarus booked her spot in the semi-finals with a 3-6, 6-2, 6-4 victory over Spanish sixth seed Carla Suarez Navarro.
Sabalenka next faces fifth-seeded Croatian Donna Vekic, who defeated American qualifier Kristie Ahn 7-5, 6-0.