00:26 CET - That concludes our coverage for tonight but be sure to come back tomorrow morning for more action from the ATP and WTA tour.
00:23 CET - Finally from the tennis today, Mattia Bellucci (23) has downed qualifier Mees Rottgering (17) on his ATP debut 6-3, 6-2 to progress in Rotterdam.
00:08 CET - The final match of the day in Dallas has finished and Rinky Hijikata (23) has won comfortably 7-5, 6-3 against Adrian Mannarino (36).
22:09 CET - It was a valiant fight from veteran and former Rotterdam champion Stan Wawrinka (39) in his match against Daniil Medvedev (28) - another champion here - but the Russian has come through their contest 6-7(8), 6-4, 6-1 to progress into the next round.
Back to Dallas, where American Christopher Eubanks (28) has been seen off in the first round by eighth seed Matteo Arnaldi (23) in straight sets 6-3, 6-4.
21:32 CET - Play has finished in Cluj-Napoca for the day with home favourite Sorana Cirstea (34) shocked by Canadian qualifier Marina Stakusic (20) in three sets 1-6, 6-1 6-4.
20:38 CET - Over to Dallas, where Alejandro Davidovich Fokina (25) has taken apart Brandon Holt (26) to win the opening game of the day 6-1, 7-5.
19:02 CET - In Abu Dhabi, Liudmila Samsonova (26) will be sick of the sight of the name Kudermetova today...
After Polina Kudermetova (21) withdrew from their game, her older sider Veronika Kudermetova (27) took the spot and beat the fifth seed 5-7, 6-1, 7-6(5) in nearly three hours.
Meanwhile, in Romania, fourth seed Anhelina Kalinina (27) has prevailed in her match against Elena Gabriela Ruse (27) 6-2, 6-3.
17:40 CET - Over in Cluj-Napoca, Caroline Dolehide (26) has avoided an upset by getting over the line to beat Daria Snigur (22) 7-5, 2-6, 6-4.
16:57 CET - Stefanos Tsitsipas (26) is the next man through in Rotterdam, downing Harold Mayot (22) 6-1, 7-5 in just under an hour and a half.
Meanwhile, Katie Volynets (23) and Lulu Sun (23) both claimed victories in Abu Dhabi.
15:37 CET - Ashlyn Krueger (20) has sealed her spot in the next round in Abu Dhabi after a hard-fought 6-3, 6-7(4), 6-3 victory over compatriot McCartney Kessler (25).
14:48 CET - Some of the world's best are meeting in Rotterdam this week, and we have our first result from the Netherlands, with eighth seed Hubert Hurkacz (27) seeing off Flavio Cobolli (22) in straight sets 6-3, 6-2.
12:42 CET - Viktoriya Tomova (29) is through in Cluj-Napoca after a topsy-turvy 3-6, 6-4, 6-1 win over Mayar Sherif (28), while Japanese teenager Wakana Sonobe (17) has beaten Yue Yuan (26) 6-4, 6-3 in Abu Dhabi.
11:05 CET - Play is already underway at WTA tournaments in Abu Dhabi and Cluj-Napopca, with Liudmila Samsonova (26) and Anhelina Kalinina (27) the headline names involved on a relatively quiet opening day.
Later on, Hubert Hurkacz (27), Stefanos Tsitsipas (26) and Daniil Medvedev (28) all take to the court at the ATP 500 event in Rotterdam, while play starts at 19:00 CET in Dallas, where Matteo Arnaldi (23) is among those in action.
09:00 CET - Good morning and welcome to our coverage of today's tennis!