World No. 1 Aryna Sabalenka led the way into the US Open quarter-finals, beating American Taylor Townsend in straight sets on Sunday to keep her bid for a rare three-peat on track. 

Sabalenka rallied from 1-3 down in the second set for a 6-4, 6-3 victory. Sabalenka needed all of her resolve against the multi-faceted Townsend, whose blistering service returns and net prowess flummoxed the Belarusian star.