Britain's Katie Boulter backed up the biggest win of her career by beating Caroline Garcia to reach the Birmingham Classic quarter-finals.

Garcia double-faulted to lose the first set and was still unhappy early in the second, with Boulter taking advantage.

"I'm absolutely ecstatic right now," Boulter, 25, said.

She will face former world number one Simona Halep for a place in the semi-finals after the Romanian beat Britain's Harriet Dart 6-3 6-2.

Dart had made a strong start against the second seed, breaking her in the opening game but back-to-back breaks in the fourth and sixth games enabled Halep to turn the first set around and the 2019 Wimbledon champion was not troubled again.

Boulter finding form in time for Wimbledon

Boulter has struggled with illness and injury over the past three years and is just returning from a leg injury she sustained in March.

She has been given a wildcard into the main draw at Wimbledon, which starts on 27 June, and is finding some good form just in time.

"I've worked so hard the past few weeks with my injury," said Boulter in her on-court interview.

"It kind of makes it feel worthwhile - and all the tough moments that I went through, and pushing through, really got me through today. I'm really happy to be in the quarter-finals and am looking forward to another good match."

A close first set was settled by a tie-break, and more specifically the double fault that Garcia never seemed to recover from.

The French world number 74 was frustrated that the umpire had overruled the line judge by calling her first serve out on that final point and she spent the changeover at the end of the set complaining and taking it out on her racquet and water bottle.

She was still shaking her head at the start of the second set and Boulter made the most of her opponent's distraction to break early and go 3-0 up.

The British world number 141 fended off a break point in the fifth game of the second set before immediately breaking and then serving out the match to love.

She is joined in the last eight by Chinese eighth seed Zhang Shuai,who came from behind to beat Croatia's Jana Fett 5-7 6-3 6-3, and Romanian sixth seed Sorana Cirstea, who won 6-1 6-1 against Aleksandra Krunic of Serbia.

Third seed Camila Giorgi also advanced, with a 7-6 (9-7) 6-4 victory over Czech Tereza Martincova, while Croat Donna Vekic beat American Caty McNally 7-5 6-3.