The world number one eased to a 7-6 (7/2), 6-2 triumph against Tallon Griekspoor for the winning point after Matteo Berrettini had put the defending champions ahead with a convincing 6-4, 6-2 win against Botic van de Zandschulp.

Sinner ends 2024 with titles at the Australian Open, US Open and the ATP Finals.

"The whole team is amazing, we tried to defend our title and we have done it, so we're extremely happy... there's a lot of work behind it," said Sinner as Italy won the Davis Cup for a third time.

Italy became the first team to defend the title since the Czech Republic in 2013, and the fifth nation to win it along with the Billie Jean King Cup in the same season.

Strong Italian support, along with an orange wall of Dutch fans, made for a fine atmosphere at the Martin Carpena arena, with the Netherlands in the final for the first time in 104 years of trying.

However defeating Sinner this year has been nigh on impossible for most players, let alone with the pressure of carrying a nation's hopes on their shoulders.

Griekspoor, ranked 40th, has now lost all six meetings with Sinner but battled remarkably well, forcing Sinner to save two early break points.

Serving brilliantly, Griekspoor twice held to love and hit two aces in the 12th game to force a tie-break.

Sinner secured an early mini-break and another for a 5-2 lead, firing down his 12th ace to take the first set.

The Italian brought up and converted his first break point of the match to take a 2-1 lead in the second set.

Griekspoor produced a backhand winner to drag his way back on serve but undid his good work with a double fault that allowed Sinner to break again for a 3-2 lead.

The game was up for the Dutch and Sinner broke again in the seventh game before sealing his triumph with his fourth match point with a scorching serve Griekspoor could not return.

"I had no other option than playing a high level match -- if you want to have a chance against Jannik in this kind of form, this kind of shape, this kind of confidence," said Griekspoor.

"Jannik is very tough to beat, especially, with the season he had, he deserves all of it."

Netherlands captain Paul Haarhuis was part of the last Dutch team to reach the semi-finals 22 years ago.

"I don't have a love relationship with second place, I have a hate relationship with second place," said Haarhuis.

"Even though I'm unbelivably proud of the guys, for now it feels (terrible)."

'I missed that'

Berrettini edged the first set against Van de Zandschulp but hit his peak in the second and left the Dutchman no chance, winning in 76 minutes.

The world number 35, who came to support Italy as they ended a 47-year wait for the trophy in 2023 as he missed out with an ankle injury, was crucial in their Davis Cup defence.

The 28-year-old paired up with Sinner to help Italy triumph in a doubles decider against Argentina in the last eight, before winning his semi-final singles rubber against Australia's Thanasi Kokkinakis.

"It feels unbelievable, it feels really great to be on court -- if you win it's better, but being able to be healthy, here and enjoying this kind of atmosphere is the most important thing for me, because I missed that," said Berrettini.

"I definitely feel that my level never really left. When you're struggling physically and mentally it's not easy to play your best tennis."

Van de Zandschulp, ranked 80th, became the last player to defeat Rafael Nadal before the Spanish superstar headed into retirement earlier in the week.

However he was blown away by Berrettini, who moved ahead in the ninth game of the first set. The Italian opened up three break points and took the first to claim a 5-4 lead.

In the second set Berrettini, who was Wimbledon runner-up in 2021, broke in the third game and again in the seventh.

The Italian produced 10 forehand winners and 16 aces on his way to victory, teeing up Sinner to finish the tie.