Comeback victories from Jessica Pegula and Emma Navarro against Great Britain sent the United States through to their first Billie Jean King Cup final since 2018 in Shenzhen on Saturday.

After Navarro opened proceedings with a hard-fought 3-6, 6-4, 6-3 win over Sonay Kartal, Pegula sealed the tie for the Americans with a 3-6, 6-4, 6-2 win over Katie Boulter.

The victory means USA have now reached the BJK Cup final for a record 31st time and they will take on defending champions Italy in Sunday's final for a shot at adding a 19th title to their storied history in the competition.

"It's the first time I will be in the final," said Pegula, who made her BJK Cup debut for the USA in 2019.

"I think everybody on the team it'll be our first time. So it'll be a new experience for us but there's no one else I'd rather share it with. We're excited to be back and hopefully take the title."

The seventh-ranked Pegula and 18th-ranked Navarro were considered heavy favourites in their respective singles matches but Boulter and Kartal gave the American pair a run for their money.

Boulter, ranked 55 in the world, entered the clash holding an impressive 14-6 win-loss record in BJK Cup singles matches, and with a 1-0 head-to-head record against Pegula.

The 29-year-old Briton enjoyed a blistering start, breaking Pegula twice to grab a one-set lead in 36 minutes.

The duo traded breaks in the second before Pegula eked out another advantage to level the match.

- 'Never give up' -

As Boulter's error count rose, Pegula found her game in the decider as she surged ahead 5-2 and wrapped up the semi-final in just under two hours.

"I think watching my teammate Emma win earlier definitely motivated me a lot and inspired me a lot, the way she turned that match around," said Pegula.

"If it wasn't for her, I wouldn't have been in such a good position to win the match today and to beat Great Britain, so honestly that motivated me a lot.

"I had to just find a way to compete. I felt like my level wasn't there, she was playing at a high level and then I was able to turn it around there."

Earlier at the Shenzhen Bay Sports Centre, Navarro rallied back from a set and break down to overcome a stubborn Kartal.

A see-saw first set witnessed five breaks of serve but it was Kartal who managed to consolidate her advantage as she grabbed a one-set lead in 37 minutes.

Navarro had to recover from a break deficit twice in the second set before she upped her level, utilising some sharp angles and clever shot-making, to break Kartal in game 10 and even up the contest.

The 24-year-old American could not consolidate her first break of the deciding set but struck again to complete a crucial opening point for her team.

"I feel a ton of pride playing for my country," said Navarro. "It means the world to me to be able to have the American flag on my chest. I never give up anyway, but I’ll especially never give up when I have the American flag on my chest."

This is the third time in the last four years that Great Britain have lost in the semi-finals of the BJK Cup.