Great Britain engineered the upset of the week at the Billie Jean King Cup Finals in Glasgow, sweeping Spain to advance to the semifinals for the first time since 1981.

No.115 Heather Watson sparked Team GB's upset hopes by routing Nuria Parrizas Diaz 6-0, 6-2 in the opening rubber. No.98 Harriet Dart then earned the biggest upset of the day, defeating No.14 Paula Badosa 6-3, 6-4 to win the tie for Great Britain. The victory was Dart's third Top 20 win of 2022 after beating Elina Svitolina at Indian Wells and Daria Kasatkina at the US Open. 

But after an opening day 2-1 loss to Kazakhstan, Great Britain could only advance by sweeping Spain. Alicia Barnett, 29, and Olivia Nicholls, 28, embraced the challenge and defeated Aliona Bolsova and Rebeka Masarova 7-6(5), 6-2 to book the home nation a spot in the Billie Jean Cup semifinals.

Great Britain will face Australia for a spot in the final. Led by Ajla Tomljanovic, the Australians defeated Belgium to win Group B and advance to the semifinals for the second consecutive year.

More from Glasgow: Australia advances to semifinals; Canada wins

The Czech Republic kicked off its tournament by holding off a resilient Polish side to set up a winner-take-all match with the United States on Friday. Led by Karolina Pliskova, Karolina Muchova, and Doubles No.1 Katerina Siniakova, the Czechs are eyeing a 12th Billie Jean King Cup title this week at the Copper Box.

Magda Linette once again kept Poland in the mix. A day after defeating Madison Keys, the World No.49 defeated former No.1 Pliskova, 6-1, 6-4 to force a decisive doubles rubber. But just as against the Americans a day before, Poland could not seal the upset win. Siniakova and Marketa Vondrousova completed the 3-2 win by defeating Katarzyna Kawa and Magda Linette, 6-2, 6-3.