Britain stormed into the knockout stage of the United Cup mixed team tournament on Sunday as Dan Evans came through a gruelling encounter against Spain's Albert Ramos-Vinolas with a 6-3 1-6 6-3 win that gave his team an unassailable 3-1 lead.
Britain began the day with a 2-0 advantage in the tie thanks in part to Cameron Norrie's win over Rafa Nadal on Saturday, but an ailing Paula Badosa dragged Spain back into contention as she shrugged off leg cramps to beat Harriet Dart 6-7(6) 7-6(4) 6-1.
Evans, who recovered from illness to be part of the $15 million prize money event, then showed his battling qualities to overcome Ramos-Vinolas - a late replacement for Pablo Carreno Busta - and help Britain top Group D.
They will now take on the winner of Group C comprising the United States, Czech Republic and Germany in the ‘city final’ at Sydney's Ken Rosewall Arena on Wednesday.
Spain next play Australia, who are without Ajla Tomljanovic after she withdrew from the tournament to recover from a minor knee issue before the January 16-29 Australian Open. Nick Kyrgios also unavailable as he gears up for the major.
Petra Kvitova earlier beat Laura Siegemund 6-4 6-2 for her second straight victory in the tournament as the Czechs secured a 3-0 lead in their tie against Germany.
Oscar Otte earned Germany their first win when he defeated Dalibor Svrcina 7-6(1) 6-2 before Siegemund and Alexander Zverev teamed up for another consolation win over Marie Bouzkova and Jiri Lehecka 6-4 7-6(1).
The Czechs have one win and a defeat from two ties following their opening round robin loss to the United States, who take on Germany next in Group C.
Bulgaria's Alexandar Lazarov and Isabella Shinikova won the first ever United Cup deciding mixed doubles meeting in Perth, saving a match point to beat Belgium's David Goffin and Elise Mertens for a 3-2 triumph in Group A.
Casper Ruud sealed Norway's only victory in their 4-1 Group E defeat by Brazil, as he downed Thiago Monteiro 6-3 6-2. Poland went 3-1 up over Kazakhstan in Group B, with Hubert Hurkacz and Magda Linette winning their matches in Brisbane.
Croatia ended Argentina's chances of advancing from Perth, going up 3-0 to hand them a second straight Group F loss.
The United Cup is being played in three cities with two group winners from each venue meeting to determine who reaches the last-four stage.
The fourth semi-finalist will be the ‘city final’ runner-up with the best record from their three matches. Sydney will host the final on January 8.
Additional reporting by Reuters.