Aryna Sabalenka roared past Coco Gauff to avenge her French Open final defeat and secure her place in the WTA Finals last four alongside Jessica Pegula.
Sabalenka, Gauff and Pegula went into Thursday's matches in Riyadh knowing only two of them would progress from the Stefanie Graf Group.
American Pegula won 6-2 6-3 against already-eliminated Jasmine Paolini, meaning a straight-set win for defending champion Gauff would have knocked world number one Sabalenka out.
Gauff also had the statistical edge, having come out on top in their previous meeting at Roland Garros in June - with Sabalenka putting in a performance she later described as the "worst final I ever played".