Harriet Dart claimed one of the best wins of her career against Spain’s Paula Badosa to put Great Britain within one victory of an unlikely semi-final spot at the Billie Jean King Cup Finals.

Defeat by Kazakhstan on Tuesday coupled with Spain’s 3-0 victory over the same opponents at Glasgow’s Emirates Arena the following day meant Britain knew only a whitewash of the five-time champions would be enough to progress.

They went into the tie as big underdogs, but Heather Watson cruised to a 6-0 6-2 victory over Nuria Parrizas Diaz and Dart built on that with a brilliant 6-3 6-4 success against world number 13 Badosa.

That set up a straight fight in the doubles for a place in the last four.

Dart fought back tears in her on-court interview as she said: “It’s so awesome being here in Britain and being able to host this event. I’m just so happy to keep this one alive.”

The 26-year-old has beaten a number of highly ranked players this season but was a big underdog, especially given the form Badosa showed in beating Wimbledon champion Elena Rybakina on Wednesday.

But, with the bigger crowd creating a much-improved atmosphere, Dart, ranked 98, picked up where Watson had left off, breaking Badosa in the opening game.

The Spaniard has been erratic this year and Dart stood up to the power of her opponent extremely well, drawing regular errors and even striking more winners.

When a successful challenge to a second serve earned Badosa a reprieve on set point, Dart stepped in and struck a backhand winner to break for a third time.

Badosa improved in the second set and consistently pressured the Dart serve, but the British number two held firm superbly and then seized her chance when her opponent faltered again.

Captain Anne Keothavong opted to play Watson rather than Katie Boulter, who produced an error-strewn display on Tuesday, in the opening rubber and the 30-year-old fully justified that decision with a sparkling display against a player ranked 61 places higher.

Heather Watson celebrates her victory with captain Anne KeothavongHeather Watson celebrates her victory with captain Anne Keothavong (Jane Barlow/PA)

The veteran of the side having made her debut back in 2011, Watson never looked like faltering after winning the first seven games and eased to her 31st victory in the competition.

“I had so much fun out there,” said Watson. “I was smiling over at my team a lot. I loved every second out there and I think my tennis showed that. I think I played really well.”

Australia became the first team to book their place in the last four with a 3-0 victory over Belgium.

Belgian number one Elise Mertens, who dashed to Glasgow after winning the doubles title at the WTA Finals in Texas on Monday evening, retired during the third set of her clash against Ajla Tomljanovic with a shoulder injury.

Belgium played their two matches before the Czech Republic, who had two players at the WTA Finals, contested their first tie, which drew criticism from captain Johan Van Herck.

Belgium's Elise MertensElise Mertens retired injured during her match with Ajla Tomljanovic (Jane Barlow/PA)

“We were not helped by the situation,” he said. “What happened with Elise, I don’t think it’s very correct. It had a huge impact on what we had to go through here, especially Elise now with an injury.

“So it’s something where I think we, as a small country, have to pay a price for not being the Czech Republic that starts today or the US that can play in the evening.”

Canada will take on Switzerland on Friday for a place in the semi-finals after beating Italy 3-0, with Leylah Fernandez claiming a 6-0 6-0 victory over Martina Trevisan.