Muguruza and Jabeur edge to victory in Dubai

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.