Germany completed a remarkable comeback to beat Argentina in a thrilling doubles decider and set up a Davis Cup semi-final against Spain.

Kevin Krawietz and Tim Puetz saved three match points in a final-set tie-break to overcome Horacio Zeballos and Andres Molteni 4-6 6-4 7-6 (12-10) in a gruelling contest lasting two hours and 31 minutes.

Argentina had put the first point on the board when world number 60 Tomas Etcheverry hit 23 aces to beat Jan-Lennard Struff 7-6 (7-3) 7-6 (9-7) in a high-quality encounter.

But world number three Alexander Zverev launched Germany's recovery, beating world number 21 Francisco Cerundolo 6-4 7-6 (7-3) to force the deciding doubles.

Zverev, the only top 10 singles player competing in the Davis Cup this week, was not at his best but a brilliant tie-break performance kept Germany's hopes of progressing to a second straight semi-final alive.

Those hopes were on their way to being extinguished when Zeballos and Molteni dominated the opening set of the doubles rubber.

But Krawietz and Puetz, who have three Grand Slam doubles titles between them, took the second set before a stalemate in the decider sent the match to a tie-break.

The Germans missed four match points, including three in a row, in an astonishing tie-break before clinching victory with the fifth.

"Incredible. There's not many matches you play in your career like that," said Puetz. "It feels better to win in the end but what a great match and a great Davis Cup tie."

Not since their title-winning 1993 campaign have three-time champions Germany reached the final of the tournament.

Earlier on Thursday, Spain brushed aside the absence of Carlos Alcaraz to come from behind and beat the Czech Republic 2-1 and move one step closer to a first title in six years.

Spain will meet Germany in Bologna on Saturday with two-time defending champions Italy taking on Belgium in the first semi-final on Friday.

No Alcaraz, no problem - Spain 'still alive'

A "heartbroken" Alcaraz pulled out of Spain's squad for the Finals on Tuesday after the new world number one was advised not to compete because of swelling in his right hamstring.

In the absence of their talisman, things started shakily for the Spanish team after the big-serving Jakub Mensik - with 20 aces - defeated Pablo Carreno Busta 7-5 6-4.

World number 36 Jaume Munar, with his first singles win at the Davis Cup, took the tie to the deciding doubles with an impressive 6-3 6-4 victory over US Open quarter-finalist and world number 17 Jiri Lehecka.

Czech captain Tomas Berdych switched Mensik in for the doubles but to no avail as he and Tomas Machac - both singles specialists - fell 7-6 (10-8) 7-6 (10-8) to Marcel Granollers and Pedro Martinez.

The Czechs were left to rue their missed opportunities in a two-hour tussle, having held a 4-1 lead and three set points in the first-set tie-break, while two further set-point chances were missed in the one in the second set.

Former doubles world number one Granollers said: "We are really happy that we fought hard for all of the team. We believed, and here we are in the semi-finals.

"Last year was difficult for us [exiting in the quarter-finals], but we know this competition is very difficult. We can see here how good the teams are. We have a young team, but we are still alive."

Spain have not reached the last four of the Davis Cup Finals since winning the title in 2019.