Finland's Emil Ruusuvuori, left, congratulates Australia's Alex de Minaur at the end of their Davis Cup semi-final tennis match between Finland and Australia in Malaga, Spain, Friday, Nov. 24, 2023. Photo: AP
The world number 12 wore down Emil Ruusuvuori in a 6-4, 6-3 straight sets triumph, after Alexei Popyrin beat Otto Virtanen 7-6 (7/5), 6-2 in the first singles rubber.
Australia, who last won the competition in 2003, will face Novak Djokovic's Serbia or Jannik Sinner's Italy in Sunday's final.
"For us this cup is a priority, we do everything we can to represent Australia, with pride and passion," said De Minaur.
"It's not too bad to reach another final."
Australia captain Lleyton Hewitt said reaching the final means "a hell of a lot" to him.
"Our boys dug really deep ... we're a tight-knit unit and we've given ourselves another opportunity on Sunday," he added.
De Minaur produced a remarkable comeback against the Czech Republic in a rollercoaster classic to help his country reach the semi-finals but had a gentler ride this time at the Martin Carpena arena.
Although he and Hewitt have been highly critical of the revamped Davis Cup format, the 24-year-old expertly steered his team into their 49th final.
The 28-time champions, behind only the United States, ended Finland's fairytale run with little fuss, and the captains agreed not to play the deciding doubles.
Nordic fans outnumbered those in green and gold, just as they did for their superb last eight victory over reigning champions Canada on Tuesday, but this time left disappointed.
Finland's number one, Ruusuvuori, 69th in the world, missed the Canada win with a shoulder problem and he had heavy lifting to do after Virtanen's defeat.
Ruusuvuori exchanged breaks with De Minaur, with the Australian finally converting his sixth break point in the third game to get back on serve and never looked back.
De Minaur broke a second time when the Finn hit a backhand into the net and consolidated to move 4-2 ahead as he hit his stride.
Ruusuvuori conceded a third break by slapping a forehand into the net and despite breaking back with a lovely drop shot, De Minaur served out to wrap up the set.
At the start of the second he saved a break point against an aggressive Ruusuvuori and then broke himself for a 2-1 lead, which he protected.
De Minaur clinched victory with a superb backhand winner, hit on the rise.
Hewitt, who played in Australia's last Davis Cup win 20 years ago, knows the final will be tough, whether it is against world number one Djokovic's Serbia, or number four ranked Sinner and Italy.
"It's tough either way," said Australia's captain.
"Obviously the number ones are both absolute quality players -- they are as good as anyone going around at the moment."
Popyrin, 40th in the world, had paved the way for De Minaur by showing his quality in the second set to defeat his 171st ranked opponent.
"Alexei stood up when he needed to today," added Hewitt.
After a tight first set decided by tie-break, the Finn double-faulted to hand his opponent a break for 4-2, and then went wide as the Australian broke again to seal the win.
"It's nerves that I have never experienced before in my life, the nerves playing the first tie, the first rubber of a Davis Cup, winning my first live rubber of a Davis Cup (tie)," Popyrin said.
"I just had to keep my head steady and just really focus on my serve and try to capitalise on opportunities when they came."
Finland captain Jarkko Nieminen was disappointed not to make further history by taking the team to the final but said the experience was "amazing".
"(I feel) empty when you realise that this trip for this year is over, (the) amazing trip that we have had," said Finland captain Jarkko Nieminen.
"(I) appreciated the effort of the team, players, the crowd."
Serbia face Italy on Saturday in the second semi, ahead of Sunday's final.
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