Harriet Dart dug deep to win a crucial singles match and take Great Britain’s Billie Jean King Cup tie against the Czech Republic to a doubles decider.

Raducanu lost 6-1 6-1 to 2019 French Open finalist Marketa Vondrousova and was hampered by a blister on her foot.

With Raducanu sitting out, Dart is set to lead Britain in the crucial doubles – although she too had a fitness issue.

Dart, 25, seemed to have a problem with her foot in the third set against Fruhvirtova but said after clinching victory she would be “ready if selected”.

Katie Swan and 20-year-old Sonay Kartal – named in the British squad for the first time – are the other options available to captain Anne Keothavong on the outdoor clay in Prague.

The winner of the deciding doubles match will clinch a 3-2 victory for their nation and ensure they qualify for November’s 12-team finals.

The runners-up will face a play-off tie during the same week.

However, Britain are among the countries bidding to stage the finals and could also still qualify as the host nation.

Dart typifies British fight as ‘underdogs’ force decider

Keothavong’s team were the huge underdogs going into the tie, with the hosts having a depth of talent and great pedigree in this event.

Even without big-name trio Barbora Krejcikova, Karolina Pliskova and Petra Kvitova, the Czechs were in a strong position after US Open champion Raducanu lost to Vondrousova in Saturday’s first singles rubber.

But experienced captain Petr Pala made a shock move by picking Fruhvirtova instead of world number 50 Tereza Martincova – and it may yet prove to be a costly decision.

Dart suffered a heavy defeat by Vondrousova on Friday but showed no signs of any scars as she made a confident start against Fruhvirtova.

The 25-year-old Londoner, who broke into the world’s top 100 recently after reaching the fourth round at Indian Wells, asserted her authority and eased to the opening set in 29 minutes.

When she moved into a 3-0 and 40-0 lead in the second set, the manner of victory looked as though it would be routine.

Even though Fruhvirtova managed to hold serve in that game, Dart still had the chance to serve out herself at 5-2 but was unable to take her first match point before going on to be broken for 5-3.

Another match point came Dart’s way in the ninth game, only for Fruhvirtova to show further resistance.

The Czech held and then won the next three games – with Dart showing her frustration by throwing her racquet – to force a deciding set.

At the start of the third, Dart again showed her ability to reset and moved 5-0 in front before eventually serving out victory at the fourth attempt in the match.

“I definitely think I gave my team a little bit of a heart attack,” said Dart.

“It’s natural that I was a bit nervous to try and close it out. I was happy that I was able to reset after the second set. I’m really proud of myself to get through.”

Raducanu hampered by more physical problems

Raducanu, who beat Martincova on Friday to level the tie at 1-1, was aiming to put Britain into the lead for the first time and give the momentum to a new-look side.

But, in what was only her second senior match on clay, the world number 12 came up against a wily opponent in Vondrousova, who is a natural on the surface and has proved that with her results.

Raducanu, 19, was unable to cope with her opponent’s variety and court-craft in a one-sided first set, which lasted just 26 minutes.

The Briton needed to go off court for treatment before the start of the second set, for a blister on her right foot, and struggled to move properly when the match resumed.

Vondrousova, ranked 32nd in the world, moved 2-0 ahead but then seemed unsettled by Raducanu’s lack of movement and lost concentration.

Raducanu was gifted a break back, only for the Czech to refocus and win the next four games to seal victory in 62 minutes.

“I never played in such cold weather. I am happy to be through,” said 22-year-old Vondrousova.

“The score looks easy but it was a tough match and she was a bit injured. I had to focus and I’m happy with my game.”