Garbiñe Muguruza opened up her title defence at the Dubai Duty Free Tennis Championships with a 7-6, 2-6, 6-2 win over Czech qualifier Katerina Siniakova.
The fourth seeded Spaniard won the tricky encounter in 2 hours and 24 minutes.
In the second round, she will take on Veronika Kudermetova of Russia, who defeated former World No.1 and 2010 Dubai finalist Victoria Azarenka 6-3, 6-4.
Top seed Aryna Sabalenka of Belarus beat Marta Kostyuk of Ukraine 6-4, 6-1, while Tunisia's Ons Jabeur overcame former World No.2 Vera Zvonareva 6-2, 2-6, 7-5.
Elsewhere, no.9 seed Danielle Collins of the US retired from her first-round match against Marketa Vondrousova of the Czech Republic due to dizziness (2-6, 3-0).
The 38th-ranked Vondrousova will next face Russia's Varvara Gracheva, who defeated Australian Ajla Tomljanovic 6-1, 7-5.
Captains will be the only ones allowed to speak to the referee and discuss a decision during matches at the upcoming European Championship in a bid to facilitate clearer communication.
Substitute Jhon Duran scored two late goals as Aston Villa fought back to salvage a 3-3 home draw with Liverpool on Monday and take a significant step towards a place in the Champions League next season.
Arsenal's Leandro Trossard capitalised on dreadful defending to secure a 1-0 win against Manchester United that saw the Gunners climb back to the top of the Premier League, ensuring the title race will be decided on the final day.
UAE Team Emirates rider Tadej Pogacar has retained his overall lead after Dutchman Olav Kooij won stage nine of the Giro d'Italia on Sunday, pipping Jonathan Milan by half a wheel right at the finish line in a breathless sprint at the end of a 214-km ride from Avezzano to Naples.