00:00 CET - That's all from us today on the Tennis Trakcer but be sure to tune in tomorrow for a recap of the overnight results from Santiago, Acapulco, Merida and Austin.
23:45 CET - There have been some upsets around the tournaments starting in Santiago, where seventh seed Nicolas Jarry (29) has lost his opening match to Camilo Ugo Carabelli (25) 5-7, 6-3, 7-6.
Over in Austin, third seed Peyton Stearns (23) is out after losing 6-2, 6-3 to Varvara Gracheva (24).
And finally, to Merida, where sixth seed Marta Kostyuk (22) has been toppled by Daria Saville (30) 6-4, 7-6 in the first round.
21:55 CET - Remaining in Austin, top seed Jessica Pegula (31) is into the second round after Arantxa Rus (34) retired from their match with Pegula one set to the good.
Earlier, both Cristina Busca (27) and Ena Shibahara (27) progressed as well with wins.
20:40 CET - The action is underway in Austin for the day with returning veteran Petra Kvitova (34) losing out in her first-round clash against Jodie Burrage (25), 3-6, 6-4, 6-4.
Although it wasn't a winning return for Kvitova, it is pleasing to see her back on the court after 17 months out for the birth of her child.
Tatjana Maria (37) has also advanced, beating Anna Bondar (27) 6-4, 4-6, 6-1.
20:00 CET - The first match of the day in Santiago has been won by fifth seed Tomas Martin Etcheverry (25), who has beaten Hugo Gaston (24) 6-2, 6-3.
19:50 CET - In the final game of the day in Dubai, Matteo Berrettini (28) has claimed a 7-5, 6-4 win over Gael Monfils (38). Next up for the Italian is Christopher O'Connell (30).
18:07 CET - Daniil Medvedev (29) has bucked the trend of seeds losing in Dubai with the top-ranked Russian downing Jan-Lennard Struff (34) 6-4, 7-6 to book his spot in the second round.
17:50 CET - Sixth seed Grigor Dimitrov (33) is out of Dubai after retiring from his first-round clash with Christopher O'Connell (30) while a set down. That's another top seed gone!
Meanwhile, fifth seed and defending champion Ugo Humbert (26) is safely through to the next round after beating Jiri Lehecka (23) with ease, 6-3, 6-0.
16:31 CET - Felix Auger-Aliassime (24) has made it through with a 7-6, 6-7, 6-3 win over Alexander Bublik (27) that was secured after a gruelling two hours and 51 minutes.
16:23 CET - There's been another big upset! Third seed Andrey Rublev (27) has been beaten 3-6, 6-4, 7-6 by French qualifier Quentin Halys (28).
13:56 CET - Italian youngster Luca Nardi (21) has fought back to beat Marton Fucsovics (33) 1-6, 6-2, 6-3.
13:35 CET - The second seed is out in Dubai! In a big upset, former Grand Slam winner Marin Cilic (36) has beaten world number eight Alex De Minaur (26) 6-2, 3-6, 6-3.
The Australian had his chances but only converted two of seven break points he had on Cilic's serve, while failing to defend any of the four the Croatian got.
12:24 CET - The eighth seed has fallen in Dubai with young French talent Arthur Fils (20) losing 6-2, 6-1 to Nuno Borges (28).
10:47 CET - Later today, Petra Kvitova (34) will play her first match since becoming a mother, taking to the court for the first time in 17 months to face Jodie Burrage (25) in Austin.
Read about how she's feeling ahead of her comeback here.
09:05 CET - The biggest action today is taking place in Dubai, where the following clashes are all on the agenda:
Marin Cilic vs Alex De Minaur - 11:00 CET
Quentin Halys vs Andrey Rublev - 13:00 CET
Daniil Medvedev vs Jan-Lennard Struff - 15:30 CET
Gael Monfils vs Matteo Berrettini - 17:00 CET
With top players also taking to the court in Austin, Merida and Santiago, there will be plenty to keep you entertained throughout the day.
07:57 CET - Things got underway in Acapulco overnight and the top players all made it through, with Casper Ruud (26), Tommy Paul (27) and Ben Shelton (22) winning in straight sets.
A clash between two Czech talents went the way of Tomas Machac (24), who beat Jakub Mensik (19) 6-4, 2-6, 6-3.
07:45 CET - Hello and welcome to Flashscore's coverage of today's tennis!