NEW YORK, NEW YORK - SEPTEMBER 07: Serena Williams of the United States returns the ball during her Women's Singles fourth round match against Maria Sakkari of Greece on Day Eight of the 2020 US Open at the USTA Billie Jean King National Tennis Center on
New York - Serena Williams booked a place in the quarter-finals of the US Open on Monday with a hard-fought, three-set win over 15th seed Maria Sakkari.
Williams required 2hr 28min to defeat the 25-year-old Greek player 6-3, 6-7 (6/8), 6-3 inside an empty Arthur Ashe Stadium at Flushing Meadows.
Williams, the tournament's third seed, will play either Bulgaria's Tsvetana Pironkova or France's Alize Cornet, both of whom are unseeded, for a place in the semi-finals.
Williams is seeking a 24th Slam that would equal Margaret Court's record for the most women's Grand Slam singles titles.
It has been more than three years since Williams won her 23rd Grand Slam title at the 2017 Australian Open -- when she was already pregnant with daughter Olympia.
The 38-year-old has come close since, reaching four major finals only to come away empty-handed.
A tournament victory at the weekend would also see her break away from Chris Evert, on six titles, as the most decorated US Open champion of the women's game in the modern era.
