Canadian teenager Leylah Fernandez continued her stunning giant-killing run at the US Open with victory over Elina Svitolina to reach her first grand slam semi-final.
Daniil Medvedev ended the run of qualifier Botic van de Zandschulp to reach the last four for a third straight year.
But 18-year-old Spaniard Carlos Alcaraz's run ended after he retired injured a set down to Felix Auger-Aliassime.
Here, the PA news agency looks back at day nine at Flushing Meadows.
Picture of the day

Quote of the day
Tweet of the day
If you haven't seen the most exciting player at the US Open, 19-year old Leylah Fernandez, you're truly missing out!! She just beat her 3rd ranked opponent and is on fire ๐ฅ๐ฅ๐ฅ๐ฅ๐ฅ๐ฅ. She's captivating the world! @leylahfernandez
โ Earvin Magic Johnson (@MagicJohnson) September 7, 2021
Syrup is the secret
The secret to all the ๐จ๐ฆ tennis success?
Maple. Syrup. ๐คฃ@leylahfernandez | #USOpen pic.twitter.com/Dgab5En4Cz
โ US Open Tennis (@usopen) September 7, 2021
Del Potro in the house
It's @delpotrojuan in Ashe!
Great to see the 2009 champion again. ๐ pic.twitter.com/QbpDU03i0n
โ US Open Tennis (@usopen) September 7, 2021
There are few more popular โ or unlucky โ players in tennis than 2009 US Open champion Juan Martin Del Potro. The Argentinian has undergone four knee operations since fracturing his kneecap at Queen's Club in 2019 but is preparing for another comeback.
Wedding bells for Halep

Former Wimbledon champion Halep headed home to Romania after losing in the fourth round to Elina Svitolina and revealed to reporters at the airport that she is marrying businessman boyfriend Toni Iuruc next week.
Brit watch
Semifinals are set in men's doubles:
๐บ๐ธ Steve Johnson & ๐บ๐ธ Sam Querrey๐บ๐ธ Rajeev Ram & ๐ฌ๐ง Joe Salisbury๐ฆ๐บ John Peers & ๐ธ๐ฐ Filip Polasek๐ฌ๐ง Jamie Murray & ๐ง๐ท Bruno Soares pic.twitter.com/c3zHfiGf5J
โ US Open Tennis (@usopen) September 8, 2021
Joe Salisbury and America's Rajeev Ram saved four match points against Australian duo Matt Ebden and Max Purcell to reach the men's doubles semi-finals in dramatic fashion. They were later joined by Jamie Murray and his Brazilian partner Bruno Soares. Salisbury is also in the last four of the mixed doubles with Desirae Krawczyk.
Fallen seeds

Elina Svitolina (5), Barbora Krejcikova (8)
Up next
Start spreading the news ๐ฝ@EmmaRaducanu | #USOpen pic.twitter.com/9BJiPAcPf7
โ wta (@WTA) September 6, 2021
The Emma Raducanu show rolls back into town as the Kent teenager faces 11th seed Belinda Bencic in the quarter-finals. They are first up on Ashe at 5pm. Later, calendar slam hopeful Novak Djokovic faces Matteo Berrettini in a rematch of the Wimbledon final.