Aryna Sabalenka overcame a major deficit to defeat qualifier Nikola Bartunkova 2-6, 7-6(2), 6-4 at the Berlin Open on June 19.
The world No. 1 trailed 6-2, 4-0 before mounting a comeback that lasted two hours and 23 minutes at Steffi Graf Stadion. Sabalenka won eight of the next 10 games and dominated the tie-break to force a deciding set.
"She played incredible tennis, not much I could do," Sabalenka said after the match. "I thought it was her match."
The 20-year-old Bartunkova mixed slices and drop shots to seize control early. Sabalenka later credited a shift toward the net for restoring her rhythm during the second set.
Sabalenka will next face Jessica Pegula in the semifinal. The Belarusian holds a 9-3 head-to-head lead over the American.