Simona Halep shrugged off injury concerns to record a straight sets victory over Anastasija Sevastova on Thursday to progress to the Qatar Open quarter-finals.
The world number two won 6-4, 6-3, hit 29 winners and needed four match points before overcoming her Latvian opponent, who is ranked 15th in the world.
Coming into the match, Halep admitted she had lingering concerns about an ankle injury which had kept her out of action since her defeat to Caroline Wozniacki in the Australian Open final last month.
But she seemed relatively untroubled breaking her opponent's serve late in each set to advance to the last eight.
"I'm really glad that I could finish it in two sets and play like I played," said Halep.
"I mean I'm really pleased with the way I played today and very confident."
She added that her ankle was painful but had not got worse during the match.
"Day-by-day I will see how it is and then I will decide if something is getting worse."
By reaching the quarter-finals, Halep has the chance of reclaiming the world's top ranking from Wozniacki if she goes one round further than the Dane.
But the Romanian said she was not concerned about rankings.
"I just want to play my matches and to win them," she said.
Halep will play 18-year-old American qualifier Catherine Bellis in the last eight, who beat defending champion and world number five Karolina Pliskova 7-6 (7/4), 6-3.
It is the first time the teenager has beaten someone ranked in the top five.
"I think it's definitely a milestone. It's great," said the 18-year-old.
She put part of her success down to eating ice cream every night in Doha, which "gives me a bit of energy".
World number four Garbine Muguruza breezed through her match against Romania's Sorana Cirstea, winning 6-0, 6-4.
"I'm very happy with the performance. I'm looking to play as many matches as I can. So it's good," said Wimbledon champion Muguruza.
All the world's top five are in action on Thursday, though the most anticipated clash is that between world number nine Angelique Kerber and the woman ranked just two places below her, Britain's Johanna Konta -- the last match on centre court.