07:54 CET - Belarusian Aryna Sabalenka (26) is in her fourth straight US Open semi-final after rolling past China's Qinwen Zheng (21) 6-1, 6-2.
Read the report here
07:45 CET - For the first time since 2009, an American man will be in a Grand Slam final! Frances Tiafoe (26) has guaranteed that overnight with a win over Grigor Dimitrov (33), who was forced to retire with an injury while two sets to one down.
23:57 CET - There are still two matches to be played in the night session at Flushing Meadows, with second seed Aryna Sabalenka (26) taking on Olympic champion Qinwen Zheng (21) and Grigor Dimitrov (33) up against home favourite Frances Tiafoe (26).
You can follow Zheng vs Sabalenka here and Dimitrov vs Tiafoe here.
Be sure to tune back in tomorrow morning to catch up on all the action!
23:28 CET - Taylor Fritz (26) has sealed a semi-final berth on home soil after a superb 7-6(2), 3-6, 6-4, 7-6(3) win over fourth seed Alexander Zverev (27) in three-and-a-half hours.
It's a maiden appearance in the final four of a Grand Slam for the American, who will face either Grigor Dimitrov (33) or compatriot Frances Tiafoe (26) for a place in Sunday's final.
21:37 CET - After an hour and 38 minutes on court, Taylor Fritz (26) and Alexander Zverev (27) are level at one set apiece in a high-quality affair.
Follow the third set right here.
19:50 CET - Next up on Arthur Ashe Stadium is a blockbuster men's quarter-final between home favourite Taylor Fritz (26) and fourth seed Alexander Zverev (27).
The German leads the head-to-head 5-4, but it was Fritz who came out on top in their last meeting - a five-set thriller just a couple of months ago at Wimbledon.
Follow the early stages of the match here.
19:28 CET - Emma Navarro (23) is a US Open semi-finalist! The American recovered from a double-break deficit in the second set to complete a topsy-turvy 6-2, 7-5 victory over Spain's Paula Badosa (26).
The 13th seed will play in the last four of a Grand Slam for the first time in her career, where she'll face either Aryna Sabalenka (26) or Qinwen Zheng (21) for a spot in Saturday's showpiece.
18:45 CET - The first set of our opening quarter-final goes the way of the American Emma Navarro (23), easing past Paula Badosa (26) 6-2 in 30 minutes - the Spaniard hampered by 16 unforced errors as she looks to battle back in the second set.
17:34 CET - Just under 30 minutes to go until the action gets going at Flushing Meadows with Paula Badosa (26), who has never reached a Grand Slam semi-final, facing home favourite Emma Navarro (23).
The pair have only faced each other once before, with the Spaniard coming out on top.
Follow the game from 18:00 CET.
16:00 CET - Good afternoon and welcome back to our Tennis Tracker on another huge day at the US Open, as the quarter-finals get underway in both the men's and women's tournaments.
First up in the day session, 13th seed Emma Navarro (23) - who knocked out defending champion Coco Gauff (20) in the previous round - takes on the resurgent Paula Badosa (26). That match gets started at 18:00 CET.
Meanwhile, in the men's event, home favourite Taylor Fritz (26) comes up against fourth seed Alexander Zverev (27) in a repeat of their epic fourth-round clash at Wimbledon in July. That quarter-final is due to get underway around 19:30 CET.
The night session is just as thrilling, with women's second seed Aryna Sabalenka (26) facing Olympic gold medallist Qinwen Zheng (21) before Frances Tiafoe (26) and Grigor Dimitrov (33) prepare to battle it out for a spot in the last four.
Check out the full men's schedule here and the women's schedule here.
