British number one Katie Boulter came through a tricky encounter with Ukrainian lucky loser Daria Snigur in straight sets to reach the Nottingham Open quarter-finals.

“It was an absolute battle, I’m really proud of myself,” said Boulter, 26.

She holds the top British women’s ranking for the first time in her career after reaching the semi-finals of the Surbiton Trophy last week.

Despite losing to Belgian Yanina Wickmayer in the last four of that grass-court tournament, Boulter jumped ahead of Emma Raducanu who has been hampered by injuries and seen her ranking plummet.

Remembered for a first-round upset at the 2022 US Open where she knocked out Simona Halep, Snigur broke early against Boulter.

Home player Boulter squandered seven break points in the sixth game of the opening set with Snigur eventually closing out the game to take a 4-2 lead.

Despite her mistakes, persistence paid off as Boulter broke back to level 4-4 and went on to take the first set in an hour and 15 minutes.

Snigur had knocked out the Brazilian second seed and defending champion Beatriz Haddad Maia in the first round but seemed to be hindered by a knee problem against Boulter.

The Briton went down another break early in the second set, but Snigur’s knee issues meant she eventually needed a medical time out midway through the second set.

Boulter capitalised on her opponent being evidently uncomfortable, winning three games in a row before confidently seeing the match out and reaching a third quarter-final on the Nottingham grass.

“I put my heart on the line and played as well as I could,” said Boulter after the match. “A couple of those games were ridiculous. It was so tough.”

Harriet Dart could set up an all-British quarter-final should she beat Ukrainian Anhelina Kalinina in her last-16 match while fellow Briton Jodie Burrage faces Poland’s Magda Linette.

Andy Murray, who won the Surbiton Trophy last week, is in action against France’s Hugo Grenier later on Thursday.

In the men’s doubles, British duo Liam Broady and Jonny O’Mara secured a comfortable 6-1 6-4 win over India’s Yuki Bhambri and Saketh Myneni to reach the semi-finals.

Joining them in the last four were fellow Britons Jacob Fearnley and Johannus Monday, who beat Anirudh Chandrasekar and Vijay Sundar Prashanth 7-6 (7-4) 6-3, and the British pairs could meet in the title match should they both win their semi-finals.