Thursday, August 21st
08:39 CET - There were a couple of notable results at tune-up tournaments overnight, with Alycia Parks beating top seed Emma Navarro 4-6, 6-3, 6-2 in Monterrey and Botic van de Zandschulp recovering from a poor start to defeat Sebastian Baez 0-6, 6-1, 6-4 in Winston-Salem.
There were also victories for Diana Shnaider, Liudmila Samsonova and Ekaterina Alexandrova.
Check out all the results in Cleveland, Monterrey and Winston-Salem via the links.
05:45 CET - Andrea Vavassori and Sara Errani defeat Iga Swiatek and Casper Ruud 6-3, 7-5, 10-6. The pair has now won back-to-back US Open mixed doubles titles.
05:35 CET - Swiatek and Ruud tie it all back up against Vavassori and Errani after winning the second set 7-5. The match is currently in its third and final set.
04:45 CET - Vavassori and Errani take the first set 6-3 against Swiatek and Ruud.
03:50 CET - Andrea Vavassori and Sara Errani defeat Christian Harrison and Danielle Collins in straight sets 4-2, 4-2 at the US Open. They'll take on Iga Swiatek and Casper Ruud in the final, which will be played shortly.
03:25 CET - Andrea Vavassori and Sara Errani take the first set 4-2 over Harrison and Collins.
02:50 CET - Next up for doubles at the US Open are Christian Harrison and Danielle Collins against Andrea Vavassori and Sara Errani.
02:48 CET - Iga Swiatek and Casper Ruud complete the comeback 3-5, 5-3, 10-8 over Jessica Pegula and Jack Draper at the US Open.
02:38 CET - Swiatek and Ruud battle back, taking the second set 3-5, 5-3 from Pegula and Draper.
02:05 CET - Jessica Pegula and Jack Draper take the first set 5-3 against Iga Swiatek and Casper Ruud at the US Open.
Wednesday, August 20th
23:59 CET - You can keep an eye on the scores in Winston-Salem here and Monterrey here, but our focus is turning to the US Open, where Jessica Pegula and Jack Draper are facing Iga Swiatek and Casper Ruud in the first semi-final of the new-look Mixed Doubles tournament.
The match will begin in an hour, and will be played under the roof due to rain in New York.
23:35 CET - With conditions still wet, it's unlikely that play will resume in Cleveland today. Click here to keep an eye on the schedule there.
23:22 CET - Martin Fucsovics has beaten fellow veteran Roberto Bautista-Agut 6-4, 6-3 in Winston-Salem, while Giovanni Mpethsi Perricard has won 6-3, 6-2 against fellow Frenchman Alexandre Muller.
22:24 CET - Sebastian Korda has advanced in Winston-Salem, with the 11th seed coming back from a set down to beat Kamil Majchrzak 6-7, 6-3, 6-4.
21:59 CET - The rain continues to fall in Cleveland, where three matches have been interrupted and one delayed.
21:21 CET - Our first result of the day comes from Winston-Salem, where third seed Luciano Darderi has been beaten 6-3, 6-1 by 13th seed Miomir Kecmanovic.
20:27 CET - It's taking a while for the tennis to get going today, with the matches in Cleveland halted due to rain for the second time in a few hours.
18:33 CET - Sorana Cirstea has moved into the last eight in Cleveland with a dominant 6-1, 6-1 win over Jil Teichmann that she sealed in just over an hour.
17:10 CET - Play has started in Cleveland with Sorana Cirstea taking on Jil Teichmann in the opening match of the day; the winner will qualify for the quarter-finals.
You can follow that match and all the action in Cleveland here.
14:00 CET - Good afternoon and welcome back to our Tennis Tracker as we look ahead to the semi-finals and final of the new-look US Open mixed doubles!
After an exciting first day of the highly anticipated event, the semi-finals get underway in the early hours of the morning, with Jessica Pegula and Jack Draper taking on Iga Swiatek and Casper Ruud at 01:00 CET.
Following that star-studded clash, Danielle Collins and Christian Harrison face doubles specialists and defending champions Sara Errani and Andrea Vavassori in the second semi-final at around 02:30 CET.
The showpiece is expected to take place a couple of hours later.
Elsewhere, there's plenty of action at tune-up tournaments in Cleveland, Monterrey and Winston-Salem, with Emma Navarro, Diana Shnaider and Gabriel Diallo among the standout names taking to the court.
Check out the full schedules in Cleveland, Monterrey and Winston-Salem via the links.