Top seed Simona Halep has eased into the WTA's Qatar Open quarter-finals with a 6-2 6-3 victory over Ukrainian Lesia Tsurenko.
Fresh from helping Romania reach their first Fed Cup semi-final, Halep made a blistering start by racing into a 5-0 lead in the opening set.
She held off a brief challenge from Tsurenko in the second set before reeling off the last five games of the match to improve her head-to-head record against her opponent to 6-0.
World No.3 Halep, who received a bye in the opening round, will next face ninth seed Julia Goerges, who put out Australia's Ajla Tomljanovic on Tuesday.
Goerges battled past American lucky loser Alison Riske 6-1 6-7 (7-5) 6-4 in a marathon encounter, recovering from 4-2 down in the final set.
German third seed Angelique Kerber is through to the last eight after accounting for Anett Kontaveit 6-1 7-6 (7-3).
Her next opponent will be Barbora Strycova, who battled past Anna Blinkova 6-0 3-6 6-0.
Fourth seed Elina Svitolina began her campaign with a 6-4 6-4 win over 2017 French Open champion Jelena Ostapenko, avenging her two previous losses to the Latvian.
A neck injury has hampered the Ukrainian, who was playing her first match since the Australian Open quarter-final defeat by eventual champion Naomi Osaka of Japan in January.
"I have been struggling since the Australian Open with my neck," Svitolina, who will meet Czech qualifier Karolina Muchova in the quarter-finals, said.
"It depends... on the practice, on the match, what I have, so it's tough to tell how I'm going to feel tomorrow, but every single day I try to get a treatment, I try to get some work done, and, you know, it's just a process."
Fifth-seeded Dutchwoman Kiki Bertens dropped the first set against Spain's Carla Suarez Navarro but roared back to go through 2-6 6-1 6-1.
Bertens will meet unseeded Belgian Elise Mertens, who beat Czech Kristyna Pliskova 6-2 7-6 (7-3) while Muchova beat Hsieh Su-wei 6-2 6-4.
Earlier on Wednesday, Czech Karolina Pliskova was forced to withdraw from the tournament due to a viral illness.
