Serena Williams says her motivation to win major trophies remains as high as ever in motherhood after reaching the US Open quarter-finals.
Williams, whose daughter Olympia turned one on Saturday, is aiming to win a record-equalling 24th Grand Slam title in New York.
The 36-year-old American former world number one is playing her seventh tournament since giving birth.
Williams, seeded 17th, has been in fine form at Flushing Meadows, dropping her first set of the tournament before recovering to win 6-0 4-6 6-3 against Estonia’s Kaia Kanepi on Sunday.
Winning the US Open for a seventh time would see her level Australian Margaret Court’s all-time record of 24 majors.
Defending champion Rafael Nadal’s progress into the US Open quarter-finals was far from smooth as he needed four sets to beat unseeded Georgian Nikoloz Basilashvili.
The 32-year-old Spaniard led by two sets to love before Basilashvili, ranked 37th in the world, recovered to take a third-set tie-break.
But the top seed broke twice as Basilashvili faded physically in the fourth to win 6-3 6-3 6-7 (6-8) 6-4.
He faces ninth seed Dominic Thiem next.
Nadal has reached at least the quarter-finals in all four Grand Slams this year – the first time he has achieved the feat since 2011.