-Argentina win first Davis Cup title after four final defeats

-Del Potro stages astonishing comeback against Cilic

-Delbonis blows away Karlovic to complete Argentina's comeback

-Del Potro played through fifth set with broken finger

Argentina lifted their first Davis Cup title after Juan Martin Del Potro and Federico Delbonis won Sunday's reverse singles to complete the South American nation's spectacular comeback in a 3-2 victory over hosts Croatia in the final.

Del Potro fought back from two sets down to beat Marin Cilic 6-7(4) 2-6 7-5 6-4 6-3 before Delbonis swept aside Ivo Karlovic 6-3 6-4 6-2 in the decisive rubber, sparking wild celebrations among several thousand away fans in the Zagreb Arena.

Argentina joined the list of Davis Cup winners after losing all four finals they had previously contested and their dismal record in the title showdown appeared set to continue when Cilic came within a set of clinching Croatia's second title.

The 2005 winners saw the red carpet pulled from under their feet, however, as a battling Del Potro launched a ferocious comeback and played through the fifth set with a broken finger on his left hand.

"It happened when I tried to catch a ball in the fifth set," Del Potro, who had struggled with wrist injuries in recent years, told a news conference before rushing back courtside to watch Delbonis pick apart Karlovic.

"This was an emotionally exhausting match and one of the biggest wins of my career. Thanks to all those who prevented me from retiring, I was very close to never playing again and, well, here I am."

Having clinched the opening set tiebreak, Cilic raced through the second set before Del Potro, who improved his record against the Croatian to 9-2 in all competitions, started his comeback with a passing shot between his legs.

He broke Cilic's serve in the ninth game of the fourth set and then held his own to draw level but fell behind again at the start of the fifth, handing the initiative back to the home crowd favourite.

Final Twist

Once again Del Potro showed nerves of steel and the heart of a lion as he broke straight back and forced the final twist to seal the contest in four hours 53 minutes, laying the path for Delbonis to finish the job.

His team mate did so superbly, holding serve throughout his one-sided contest with Karlovic as he kept running the Croatian ragged with punishing baseline shots.

The Argentine fans, including the country's former soccer World Cup winner Diego Maradona in the VIP box, treated their team to a standing ovation at the end of the tie as disappointed home supporters left the Zagreb Arena in a hurry.

Argentina coach Daniel Orsanic, who has Croatian roots, heaped praise on all his players but singled out Del Potro's heroics.

"What Del Potro did was amazing. He represents his country with so much pride and he also showed how good a player he is," he said.

"His achievement today borders on the impossible, while Federico played a perfect match and was on top of every ball throughout the contest."

A delighted Delbonis added: "The team captain elected me to play the final rubber but anyone on this team is always ready to step up."