Jannik Sinner inspired reigning champions Italy to a comeback victory over Argentina which set up a Davis Cup semi-final against Australia.
World number one Sinner kept Italy in contention after Lorenzo Musetti’s loss to Francisco Cerundolo with a commanding straight-set win over Sebastian Baez.
The 23-year-old then partnered Matteo Berrettini to a 6-4 7-5 victory against Andres Molteni and Maximo Gonzalez in the deciding doubles match to complete the turnaround in Malaga.
In a repeat of last year’s title decider, Italy face Australia for a place in Sunday’s final after they beat the United States 2-1 earlier on Thursday.
Italy are seeking to become only the sixth nation to retain the Davis Cup since the final stage was introduced 52 years ago, and first since the Czech Republic in 2013.
Germany beat Canada on Wednesday to confirm a semi-final against the Netherlands on Friday, who knocked out Spain in the final tournament of Rafael Nadal’s career.
Seeking to complete an outstanding individual season by helping Italy retain the Davis Cup, Sinner broke Baez’s serve twice in both sets in a straightforward win.
The in-form Sinner won the ATP Finals title on Sunday to cap a year in which he also won the first two Grand Slam titles of his career, however he has also been embroiled in an ongoing doping controversy.
World number 30 Cerundolo produced an outstanding performance to give Argentina the perfect start, closing out a 6-4 6-1 win over 17th-ranked Musetti by winning 12 of the last 15 games after suffering an early break.
But Sinner, who only arrived in Spain on Tuesday – two days after triumphing in Turin – returned following his singles victory to partner the excellent Berrettini and maintain Italy’s hopes of winning back-to-back titles.
Established pairing Simone Bolelli and Andrea Vavassori were originally selected to play doubles for Italy, but Italy captain Filippo Volandri’s decision to choose two of his star names paid off.
“The court is very fast and I haven’t had much time to adapt, but the most important thing was to keep Italy alive,” said Sinner.
Volandri, speaking about Sinner’s contribution, said: “He never practised on this court since he arrived. Within three minutes [of his singles match] he was perfectly comfortable.
“He is a special one.”
In a meeting between the two most successful nations in the tournament’s history, American world number four Taylor Fritz defeated Alex de Minaur, after Ben Shelton lost to Thanasi Kokkinakis to force a deciding match.
But Matthew Ebden and Jordan Thompson sent Australia, runners-up in the past two editions, through to the last four with a straight-set win over Shelton and Tommy Paul.
In a thrilling opening contest, Kokkinakis saved four match points to edge a 30-point third-set tie-break against Shelton, putting Australia ahead with a 6-1 4-6 7-6 (16-14) victory after two hours and 17 minutes in Malaga.
Fritz, who rose into the world’s top four after finishing runner-up to Sinner at last week’s ATP Finals, responded with a clinical 6-3 6-4 win against the ninth-ranked De Minaur to force a decider.
However, Ebden and Thompson proved too strong for Paul and Shelton in the doubles match and completed an efficient 6-4 6-4 win with a break of serve in both sets.
That sent 28-time champions Australia into the nation’s third successive Davis Cup semi-final and the pair celebrated with a chest bump before embracing team captain Lleyton Hewitt – winner of two Grand Slam singles titles.
Hewitt, part of Australia’s last triumphant Davis Cup team in 2003, said: “We’ve got a rich history in this competition. These boys know it’s a great honour every time you get the chance to wear the green and gold out here.
“We’ve had a group of six guys that have really put their hands up the last three or four years now. They’ve gelled together well and I’m just super proud of the whole team as a collective.”