04:15 CET - Taylor Fritz is the last player to win on Saturday night as he takes out fellow American Emilio Nava 6-4, 6-4 in a little over an hour.
03:15 CET - Leolia Jeanjean is unable to take to the court, meaning Amanda Anisimova moves on via a walkover.
03:00 CET - Aryna Sabalenka pushes through in a 7-5, 6-1 win over Marketa Vondrousova.
As for Francis Tiafoe, he is also progressing to round three after he gets the better of Roberto Carballes Baena 6-4, 6-3.
Meanwhile, there is an upset in the second round, as Terrence Atmane beats Italy's Flavio Cobolli 6-4, 3-6, 7-6 (5).
02:10 CET - Anna Kalinskaya is moving on in Cincinnati after she gets past Peyton Stearns 7-6 (4), 4-6, 6-1.
02:00 CET - Elise Mertens is able to defeat Clervie Ngounoue 3-6, 7-6 (3), 7-5 in a close second round encounter.
01:20 CET - Lorenzo Sonego progresses to the third round in Cincinnati after getting past Zizou Berg 6-3, 7-6 (4).
01:05 CET - A couple of results from the last few hours in Cincinnati. Joao Fonseca advances to the third round after Alejandro Davidovich Fokina retires. The score was 6-7 (4), 5-4 before the Spaniard could not continue.
Yue Yuan provided quite the shock by defeating Diana Shnaider 6-4, 1-6, 6-3.
Finally, Elena Rybakina turned things around in a 4-6, 6-0, 7-5 victory over Renata Zarazua.
23:20 CET - Ekaterina Alexandrova is through in the US, beating Lulu Sun 6-4, 6-2.
Meanwhile, 20th seed Ugo Humbert makes it into the next stage with a 6-3, 6-4 victory over Chak Lam Coleman Wong.
23:06 CET - Emma Raducanu is into the next round, thanks to a professional 6-3, 6-2 win over Olga Danilovic.
She is joined by Maya Joint, with the impressive Australian talent battling to a 6-4, 4-6, 6-4 victory over Brazil's Beatriz Haddad Maia.
22:37 CET - Shocks continue to roll in the US as 13th seed Liudmila Samsonova crashes out at the hands of Taylor Townsend by a scoreline of 6-2, 6-4.
22:15 CET - Sixth seed Madison Keys has survived a big scare against Eva Lys with the Australian Open champion needing a third-set tie-break to overcome her German opponent, eventually winning 1-6, 6-3, 7-6(1).
22:04 CET - Back to the women's side of the draw, where Magdalena Frech has tumbled out of contention, beaten 7-6(4), 2-6, 6-4 by Sorana Cirstea.
Meanwhile, Gabriel Diallo has made his way into the next round, seeing off Sebastian Baez in straight sets 7-5, 6-4.
21:46 CET - We had had our second shock of the evening in Cincinnati as French veteran Adrian Mannarino has taken down 19th seed Tomas Machac in straight sets, winning their encounter 6-3, 6-3.
21:35 CET - It's been an easy afternoon at the office for world number one Jannik Sinner as the Italian needed minimal time to beat Daniel Elahi Galan 6-1, 6-1.
21:25 CET - Stefanos Tsitsipas, looking to find some form ahead of the US Open, has overcome the challenge of Hungarian Fabian Marozsan, winning their encounter 7-6(3), 6-2.
20:49 CET - A seed has fallen this evening as Leylah Fernandez is defeated by Jessica Bouzas Maneiro in straight sets 6-3, 6-3.
20:16 CET - 13th seed Tommy Paul has breezed into the next round in Cincinnati with a comfortable 6-2, 6-2 victory over Pedro Martinez.
Also through is Felix Auger-Aliassime, who defeated Argentina's Tomas Martin Etcheverry 6-2, 7-6(3).
19:57 CET - It is another Frenchman who caused the second major upset of the evening as Benjamin Bonzi came from a set down against Lorenzo Musetti and piled more misery on the world number 10.
Bonzi showed great resilience to get back into the match and then delivered a brilliant tie-break performance to win 5-7, 6-4, 7-6 (7-4).
19:50 CET - World number 13 Casper Ruud's Cincinnati journey has come to an early end after a shock defeat against Arthur Rinderknech.
After edging a first-set tiebreak, Ruud failed to kick on in the second set, which allowed Rinderknech into the match. The Frenchman would take the second and third set to pull off a shock 6-7 (5-7), 6-4, 6-2 victory.
19:10 CET - The first winner of the day on the men's side of the Cincinnati draw is Holger Rune after the Dane held his nerve to come through a second-set tiebreak and defeat Roman Safiullin 7-5, 7-6 (7-5).
18:27 CET - Iga Swiatek has joined Kostyk in cruising into the next round in Cincinnati with a convincing 6-1, 6-4 victory against Anastasia Potapova.
18:05 CET - The first match of the day has finished in Cincinnati as Marta Kostyk lost just one game on the way to a dominant 6-0, 6-1 win over Tatjana Maria.
17:05 CET - So here we go for the evening as Lorenzo Musetti serves first against Benjamin Bonzi over on the ATP side of the draw.
Follow all the ATP action from Cincinnati tonight.
Meanwhile, in the WTA tournament, Iga Swiatek is underway on centre court against Anastasia Potapova.
Follow all the WTA action here.
13:30 CET - This is also a fascinating day on the WTA side of the tournament in Cincinnati with Wimbledon champion Iga Swiatek headlining action. The world number three gets her tournament up and running against Anastasia Potapova from 17:00 CET.
Elsewhere, other seeds in action are world number one Aryna Sabalenka, Montreal runner-up Elena Rybakina, Maddison Keys and Emma Raducanu.
13:00 CET - Hello and welcome to a busy weekend of action in Cincinnati!
It promises to be a star-studded Saturday with world number one Jannik Sinner making a return to action after his impressive maiden Wimbledon title last month. The Italian takes on Colombia's Daniel Galan in the final match on centre court tonight, and it should be a comfortable first match back.
Another major Italian hope at Cincinnati is Lorenzo Musetti, but the world number 10 needs to rediscover some form after a poor start to the hard-court season. He takes on Benjamin Bonzi on court 10 in one of the earliest matches of the day.
The other big-name ATP players in action this evening and overnight are Tommy Paul, Holger Rune, Frances Tiafoe and Taylor Fritz, with the latter high on confidence after a strong run to the final in Toronto last week.