Great Britain have taken the driving seat in Group F of the United Cup after defeating previous leaders, Argentina, 2-1 in a deciding mixed doubles rubber.

Captain Alex Ward’s team got off to a flying start in Sydney after British No.1 Katie Boulter breezed past Nadia Podoroska 6-2, 6-3, before the Argentinians drew level with three-time ATP finalist Tomas Martin Etcheverry coming back to beat Billy Harris 3-6, 6-3, 6-2.

Despite a change in line-up for the Argentinians in the mixed doubles, Boulter and Charles Broom managed to get the job done against Maria Loudres Carle and Etcheverry 7-6(4), 7-5 to seal the win for GB.

"Last year I played so well in singles and didn't get any mixed doubles rubbers, so I really wanted this one so badly," said Boulter after her doubles victory.

"I'm so glad we came out. I feel like we both played so great together considering it's our first time. But I'm just thrilled to get the win."

The Brits will confirm a place in the quarter-finals if they beat Australia on 1 January. If Australia wins 3-0 they will progress and if they win 2-1, it will come down to sets won % followed by games won %.

Match one: Boulter puts in commanding performance against Podoroska

World No.24 Boulter picked up where she left off from her stand out 2024 season with an impressive 6-2, 6-3 win over 2020 Roland Garros semi-finalist, Podoroska, in only an hour and 27 minutes.

"Obviously never easy to come out first match of the year, especially against someone who's going to make so many balls and make you work so hard," Boulter said.

"She'd already played a match, so I knew I was going to have to get sharp really quickly, and I'm glad I got through the line today and played some really good stuff as well."

Boulter is the only British player in the squad to have appeared at the United Cup before – where she got her career-best win over then world No.5 Jessica Pegula – and put in a leaders-type performance to get the job done.

In her first match since announcing her engagement to Australian tennis star Alex De Minaur just days ago, Boulter broke the world No.100 three times in a dominant opening set.

The British No.1 grew in confidence on serve throughout the second set as well – dropping just two points behind her first. Having stormed out to an early 3-0 lead, there was nothing Podoroska could do to prevent her seeing out the victory.

Match two: Harris edged out by Etcheverry

Harris came close to sealing what would have been the second biggest scalp of his career to date, before eventually losing out to former world No.27 Etcheverry 3-6, 6-3, 6-2 in two hours and 44 minutes.

Having defeated Etcheverry in their only previous meeting at the cinch Championships back in June, Harris looked to have the upper hand again as he saved five break points in the opener, including two on his final service game as he took a one set advantage.

Etcheverry lost his first match against De Minaur earlier in the week and was keen to make amends to keep his team in the contest. The Argentinian came back firing – after breaking on Harris’ first service game of the second, he went on to save five break points of his own to move 3-0 in front.

The world No.39 managed to serve out the set with ease and a double break to start the third all-but confirmed that the tie would move on to the deciding mixed doubles.

Match three: Boulter & Broom combine to seal the tie for GB

With the tie and group on the line, British mixed doubles pair Boulter and Broom clinched the victory for GB against Carle and Etcheverry 7-6(4), 7-5 in an hour and 31 minutes.

“There might have been a few nerves,” Brom admitted after the match. “But I feel like playing with Katie, she's so experienced. She helped me through that in a number of ways. I thought we gelled so well together on the court, good energy and the crowd was great as well getting us through in a few tight moments."

The Brits had to come back from a break down on two occasions at 2-1 and 4-3 down in a tight opening set before moving on to a tie-break.

GB wasted no time to racing off to a 6-1 lead in the breaker and despite signs of a fightback from the Argentinians, Broom got the better of Etcheverry at the net at 6-4 to take the set.

Boulter and Broom were clinical in the decisive moments of the tie. After another nail-biting set, it was the Brits who struck on a deciding deuce point at 5-5 as Boulter connected on a forehand winner to get a crucial break. The British No.1 then steadied her nerves to serve out the tie for her team.