Britain's Harriet Dart was beaten by Russian fourth seed Anastasia Potapova 4-6 6-3 6-4 in the quarter-finals of the Birmingham Classic.

But the British number four fell away against world number 21 Potapova.

"I thought it was a really high level match and I definitely had a lot of chances - overall it was a positive week," said Dart.

"Of course I wanted to do better today and to keep going but it's important just to keep building week in, week out to be able to compete with the best players in the world."

Potapova faces Latvian second seed Jelena Ostapenko in the last four on Saturday after she beat Poland's Magdalena Frech 4-6 7-5 6-2.

Elsewhere, top seed Barbora Krejcikova cruised past fellow Czech player Linda Fruhvirtova 6-3 6-2 to set up a semi-final with China's Zhu Lin.

Zhu came from a set down to defeat Canada's Rebecca Marino in her last-eight match.

'I'm heading in right direction' says Dart

Dart had looked comfortable on serve and moved 2-1 up in the second set, but was unable to convert three game points.

She lost her serve early in the deciding set but fought back to 3-3, only to be broken immediately as Potapova won in three sets for the third time this week.

Dart was bidding to reach a first WTA semi-final having lost three previous quarter-finals, all on British grass.

"It's a unique surface," added Dart who, was beaten by British number one Katie Boulter in the last eight of the Nottingham Open seven days ago.

"I've really enjoyed these couple of weeks and will just to try and use this momentum for the rest of the season.

"Today I played someone who's 21 in the world and lost 6-4 in the third, and I think there's a lot of areas I can improve on, so it's heading in the right direction."

Earlier on Friday, Dart and Nottingham Open champion Boulter both received wildcards for next week's WTA 500 tournament in Eastbourne.