Hampstead’s Harriet Dart will hope to cause another upset in the semi-finals of the mixed doubles at Wimbledon on Friday.

Ham & High: Harriet Dart and Jay Clarke during the mixed doubles on day ten of the Wimbledon Championships (pic Steven Paston/PA)Harriet Dart and Jay Clarke during the mixed doubles on day ten of the Wimbledon Championships (pic Steven Paston/PA) (Image: PA Wire/PA Images)

The 21-year-old and partner Jay Clarke knocked out 10th seeds Juan Sebastian Cabal of Colombia and American Abigail Spears 7-6 (12-10) 7-5 in the quarter-finals on Thursday.

And they now face defending champion Jamie Murray and his partner, former Australian Open singles champion Victoria Azarenka, in the last four, after they beat Dutch duo Jean-Julien Roger and Demi Schuurs 4-6, 7-5, 7-5.

Murray, who won the title with Martina Hingis last year, said: “We did well to come back. There were a lot of great rallies. It was epic.

“We don’t make it easy for ourselves but we got there and we are excited to be in the semi-finals.”

Ham & High: Harriet Dart and Jay Clarke during the mixed doubles on day ten of the Wimbledon Championships (pic Steven Paston/PA)Harriet Dart and Jay Clarke during the mixed doubles on day ten of the Wimbledon Championships (pic Steven Paston/PA) (Image: PA Wire/PA Images)

Wild-cards Clarke, 19, and Dart have exceeded their expectations and Murray is aware of the threat they might pose, adding: “They have done awesome, to be in the semis, they have beaten a lot of good teams and deserve to be there.

“We know it’s going to be a difficult match. But we are a good team as well, we’ll go out there and do our thing and try to get to the final.”

Clarke and Dart beat fifth seeds Robert Lindstedt and Yang Zhaoxuan in their first match and are dreaming of a Wimbledon final.

“Before the draw we wanted to get through round one,” said Clarke. “And then we saw the draw and hoped we’d maybe take a set.

Ham & High: Jamie Murray and Victoria Azarenka celebrate their win on day ten of the Wimbledon Championships (pic Nigel French/PA)Jamie Murray and Victoria Azarenka celebrate their win on day ten of the Wimbledon Championships (pic Nigel French/PA) (Image: PA Wire/PA Images)

“Obviously Jamie is the king of doubles, and he has a decent partner as well, so it will be a tough test but I think we are ready.”

Their match is third on Court One today, after the two women’s doubles semi-finals.