Serena Williams took another step towards that elusive record-equalling 24th grand slam title after coming from behind to beat Tsvetana Pironkova and reach the US Open semi-finals, where she will face former world number one Victoria Azarenka.
Meanwhile, second seed Dominic Thiem beat Alex De Minaur to set up a blockbuster last-four meeting with last year's runner-up Daniil Medvedev.
Here, the PA news agency looks back at day 10 at Flushing Meadows.
Picture of the day
Andrey Rublev let his suspect temperament get the better of him in his quarter-final defeat to Medvedev.
Mother's day
Williams paid tribute to her fellow mother Pironkova, who pushed the American to the limit in her first tournament in three years. Another mum, Azarenka, awaits after she beat Elise Mertens.
Shot of the day
Medvedev painting the lines with a pinpoint winner.
Performance of the day
Azarenka, who was world number one eight years ago, rolled back the years by dismantling Mertens 6-1 6-0 in just 73 minutes. Mertens, the 16th seed, did not even manage a hold of serve.
Stat of the day
Azarenka is bidding to become only the second former US Open girls' singles champions to win the women's singles title. Lindsay Davenport remains the only player to do so, winning the junior title in 1992 and the big one six years later.
Quote of the day
Shock of the day
Never mind the power outage which briefly delayed play in the first set between Medvedev and Rublev: the courtside suit star – believed to be a catering official – was back with another dazzling display of sartorial excess.
Miss of the day
Thiem hit a serve so far long he felt compelled to challenge it himself after it was called in. Somehow the line judge and chair umpire both missed it. Thiem went on to win in three sets.
Fallen seeds
Women: Elise Mertens (16)
Men: Andrey Rublev (10), Alex De Minaur (21)
Up next
Fourth seed and former champion Naomi Osaka takes on American Jennifer Brady in the first semi-final, before Williams takes centre stage against Azarenka.