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.
100 horses to compete in 30th Dubai World Cup
Tiger Woods charged with DUI after rollover crash in Florida
Germany earn comeback win over Switzerland as Dutch beat Norway
Russell edges Antonelli as Mercedes set early practice pace in Japan
Sabalenka sails past Rybakina to set up Miami Open final against Gauff
