World number one Serena Williams set a new Grand Slam record of 308 victories with a win over Yaroslava Shvedova of Kazakhstan at the US Open.
The American, 34, won 6-2 6-3 to pass Roger Federer in the all-time list of matches won at the tennis majors.
Her sister Venus went out in dramatic fashion, losing 4-6 6-4 7-6 (7-3) to Czech 10th seed Karolina Pliskova.
In the men's draw, both Swiss third seed Stan Wawrinka and Argentina's Juan Martin del Potro progressed
Wawrinka saw off Ukraine's Illya Marchenko 6-4 6-1 6-7 (5-7) 6-3 to set up a quarter-final against 2009 champion Del Potro, who led Dominic Thiem 6-3 3-2 when the Austrian retired with a knee injury.