Number five seed Jelena Ostapenko booked a place in the last 16 of the Abu Dhabi Open with victory over Danielle Collins in three sets on Monday.

Ostapenko, looking to add to the fifth career title she won in Dubai 12 months ago, edged an entertaining contest 7-5 1-6 7-5 in two hours and 19 minutes.

Fellow seeded player Anett Kontaveit was also victorious on the opening day of the tournament, but only after battling back to beat Zhang Shuai 4-6 7-6 (7-4) 6-4.

Marta Kostyuk saw off Sorana Cirstea 6-2 1-6 6-2, meanwhile, and will now face second seed Belinda Bencic in the next round.

Elise Mertens is also through to round two, where Veronika Kudermetova awaits, after dominating Martina Trevisan 6-0 6-2.

In the first main draw match at the Linz Open, Sofia Kenin let an early lead slip to lose 2-6 6-3 6-4 to Jule Niemeier.