Svitolina, who is in the hunt to earn one of the three remaining spots for the upcoming WTA Finals in Singapore, will next play sixth-seeded Wang Qiang. The Chinese player defeated Christina McHale 7-5, 6-4.
Both players struggled with their serve, resulting in a combined 39 break-point opportunities in the match. Gavrilova broke serve on nine of her 18 chances, while Niculescu converted nine of 21.
Gavrilova will next face Zhang Shuai, who defeated Dutch qualifier Lesley Kerkhove 6-1, 6-7 (4), 6-1.
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