RIYADH, Saudi Arabia (AP) — Top-ranked Aryna Sabalenka earned a third straight group-stage win at the WTA Finals by beating Coco Gauff 7-6 (5), 6-2 on Thursday, eliminating her American opponent from the tournament in the process. Sabalenka’s win means Jessica Pegula advanced to the semifinals from the group along with the Belarusian No. 1….