Tennis Tracker: Zverev battling Shelton before Rune faces Draper in Cincinnati
00:10 CET - Jessica Pegula (30) is through to the last four after a hard-fought victory over Leylah Fernandez (21). The American sixth seed needed a third set tie-break to advance, winning the encounter 7-5, 6-7, 7-6.
23:01 CET - World number one Jannik Sinner (22) has found some form with a 4-6, 7-5, 6-4 win over Andrey Rublev (25), making his way into the semi-finals.
21:00 CET - Aryna Sabalenka (26) has had a simpler route into the semi-finals thanks to a 6-3, 6-2 victory over Liudmila Samsonova (25).
19:51 CET - Iga Swiatek (23) is through to the Cincinnati semi-finals but it took an almighty effort, with the Pole beating Mirra Andreeva (17) 4-6, 6-3, 7-5in a match that lasted two hours and 40 minutes.
17:15 CET- Today's action is underway with Iga Swiatek (23) currently level with Mirra Andreeva (17) early on in the first set on centre court.
Follow the match here
13:30 CET - What's sure to be an evening full of top tennis will get underway in two and a half hours when world number one Iga Swiatek (23) takes on French Open semi-finalist Mirra Andreeva (17).
Once that's over, men's number one Jannik Sinner (23) will battle it out with sixth seed Andrey Rublev (26) for a place in the semi-finals.
10:40 CET - There was a surprise on the women's side of the draw, with Olympic champion Qinwen Zheng (21) losing 7-5, 6-1 to the unseeded Anastasia Pavlyuchenkova (33).
10:30 CET - There was quite the atmosphere in Cincinnati last night as Frances Tiafoe (26) won a titanic battle with Jiri Lehecka (22) 6-4, 6-7, 7-6.
In a thriller that lasted for just under three hours, Tiafoe had three match points in the second set tiebreak but went on to lose it 12-10 before finally finishing the job well over an hour later.
09:42 CET - Before we take a look at the rest of last night's results, we just have to draw your attention to one of the most controversial match points you'll ever see.
Jack Draper (22) secured a win over Felix Auger-Aliassime (24) with a shot that quite clearly bounced on his side of the net, but the umpire didn't realise it had done so while Draper claimed he wasn't sure.
A tough pill to swallow for Felix...
08:00 CET - Hello and welcome to Flashscore's coverage of today's tennis!