14:30 CET - Good afternoon and welcome back to our coverage of the US Open, and by the end of play, we will know all our semi-finalists on the men's and women's side of the tournament.
The four quarter-finals already played were truly extraordinary, with Ben Shelton's epic victory over defending champion Carlos Alcaraz ending one of the great days in Grand Slam history.
Can today's action live up to that?
First up, Elena Rybakina takes on Chinese star Qinwen Zheng for a spot in the semi-finals, but there is so much more at stake. Should Rybakina win, she will become the world number one for the first time - a remarkable achievement which would end Aryna Sabalenka's streak of 99-straight weeks at the summit.
The Kazakh was in formidable form against Naomi Osaka in the last round, but comeback queen Zheng stands in her way. The former world number four and Olympic champion has struggled with a serious arm injury over the last 18 months, but she is enjoying a stunning resurgence.
After coming through qualifying, Zheng has seen off both Madison Keys and Iga Swiatek, having battled back from 0-5 down in a set against both players. Can she produce another incredible result?
That is followed by a blockbuster face-off between young superstars Coco Gauff and Mirra Andreeva.
Former champion Gauff has been many people's favourites to pick up a third Grand Slam title, but Roland Garros winner Andreeva has slowly started to return to her best after a bit of a dip following her triumph in Paris.
Gauff does lead the head-to-head 5-0, though, so clearly she enjoys this matchup.
Following those matches, the men's quarter-finals begin, as former semi-finalist Karen Khachanov takes on breakout star Alexander Blockx.
However, the Belgian suffered an injury in his last-16 victory, and it is unclear whether he will be fit enough to take to the court.
Finally, top seed Alexander Zverev faces Botic van de Zandschulp, as he looks to avoid another late-night finish.
The German has a real chance to lift his second Grand Slam title after winning in the French capital earlier this year, but Van de Zandschulp could be a tricky test - if he has recovered from a five-hour, 20-minute thriller in the previous round.