Novak Djokovic sped past Austria's Dennis Novak as Serbia thumped Austria 3-0 in their Davis Cup opening match at Innsbruck on Friday.

Djokovic took an hour to beat Novak 6-3, 6-2 after Dusan Lajovic saw off Gerald Melzer 7-6, 3-6, 7-5 behind closed doors due to a resurgence of the coronavirus in Austria.

Nikola Cacic and Filip Krajinovic then beat Oliver Marach and Philipp Oswald 6-4, 4-6, 6-3.

Djokovic is attempting to end an already memorable year on a high after claiming three of the season's four Grand Slams.

"I love to play for my country, when they need me, I'm here," Djokovic said after his match.

Elsewhere Italy beat the United States 2-1 in Turin and Spain beat Ecuador in Madrid.

Backed by a hearty home crowd Italy raced into a 2-0 lead over the States thanks to wins from Lorenzo Sonego and Jannik Sinner.

Sonego, the world No.27, was ecstatic.

"I played the best tennis of my life," he claimed after seeing off Reilly Opelka 6-3, 7-6 (7/4).

Sinner then pulverised a static John Isner 6-2, 6-0 in 62 minutes.

Novak Djokovic (left)) downed Austria's Dennis Novak
Novak Djokovic (left)) downed Austria's Dennis Novak AFP / JOE KLAMAR

In the doubles rubber Rajeev Ram and Jack Sock struck back for the States in a 7-6 (7/5), 6-2 win over Simone Bolleli and Fabio Fognini to make it 2-1, while Colombia are the third team in Group E.

The 40-year-old Feliciano L?pez opened Spain's title defence with a 6-3, 6-3 win over Roberto Quiroz of Ecuador.

Pablo Carreno Busta bt Emilio Gomez 5-7, 6-3, 7-6 to put Spain 2-0 up.

"It' a gift to be back here playing the singles rubbers, I never expected it, I was supposed to play in the doubles but after everything that happened this week here I am."

"I think I did okay," he said, referring to the absence of Carlos Alcaraz, who went into quarantine on Thursday after testing positive for Covid-19.

On the opening day of the revamped 2021 finals brothers Elias and Mikael Ymer helped Sweden sweep aside Canada, France fought back to down the Czech Republic and Croatia crushed Australia.

The Davis Cup, which began life back in 1900 as a bilateral contest between Britain and the United States, was cancelled in 2020 due to the pandemic.

This year's competition sees 12 qualifiers - Australia, Austria, Colombia, Croatia, Czech Republic, Ecuador, Germany, Hungary, Italy, Kazakhstan, Sweden and USA - joined by the previous edition's semi-finalists - Spain, Canada, Great Britain and the Russian Tennis Federation.

These are joined by two wild card nations France and Serbia.

These 18 nations are divided into six groups of three, with winners and the top pair of second places going into the quarter-finals pot.

The semi-finals and December 5 final will all be played in the Spanish capital, reward for the team that won the title two years ago after 2020 was cancelled due to the Covid-19 pandemic.