ZADAR, Croatia (Reuters) - Borna Coric kept his cool to prevail in a thrilling winner-takes-all duel with fellow young gun Frances Tiafoe on Sunday and steer Croatia into the final of the Davis Cup for the second time in three years with a monumental 3-2 victory over the U.S.

Tennis - Davis Cup - World Group Semi-Final - Croatia v United States - Sportski centar Visnjik, Zadar, Croatia - September 16, 2018 Croatia's Borna Coric in action during his match against Frances Tiafoe of the U.S. REUTERS/Antonio Bronic

The 21-year-old Coric came from two sets to one down to defeat the 20-year-old debutant Tiafoe 6-7(0) 6-1 6-7(11) 6-1 6-3 and finally subdue a remarkable fightback from the Americans, who had earlier leveled the tie 2-2 from two down.

Late understudy Sam Querrey had rewarded captain Jim Courier’s gamble by taking the tie into a decider in the fourth rubber, battling back from the brink of two sets down to beat home talisman Marin Cilic 6-7(2) 7-6(6) 6-3 6-4.

Yet with everything resting on the first duel between two of tennis’s brightest young ‘Next Gen’ men, Coric overcame the loss of two very contrasting tiebreaks to book Croatia’s final date against champions France.

“That was unbelievable. This is the most special moment of my whole life,” said a thrilled Coric on court afterwards.

The French, who defeated Spain 3-2 in the other semi-final in Lille, will have home advantage in the November showdown and hope to avenge their 3-2 loss to the Croatians in the 2016 semi-final.

The self-styled men’s ‘World Cup of Tennis’ will also see a repeat of the football World Cup final in Russia with the French, 10-times Davis Cup champions, again favorites to beat the Croatians, whose only victory came in 2005.

Yet for a moment, after Coric had capitulated 7-0 in the first set breaker and 13-11 in the third set decider, the shocked fans in the Dalmatian resort feared Croatia could be on the wrong end of one of the competition’s unlikeliest comebacks.

Coric, though, demonstrated why he is seen as one of the sport’s best prospects, holding his nerve against the equally brilliant young American and proving too solid over the final two sets as he finally prevailed after four hours six minutes.

Slideshow ( 13 images )

At 2-0 down after Friday’s singles, there had not seemed the remotest chance of a U.S. team without their top two players John Isner and Jack Sock recovering to reach a first final in 11 years.

Only when 40-year-old Mike Bryan and Ryan Harrison fought courageously to claw out a five-set doubles win on Saturday, were the Americans given even faint hope of contesting the last final to be staged under the traditional Davis Cup format.

BOLD RISK

But Courier was rewarded for a bold, if slightly desperate-looking risk when he rested his No.1 Steve Johnson and instead threw Querrey into the must-win fourth rubber even though the 30-year-old had never previously beaten Cilic in six attempts.

Cilic had also become the most successful Croatian Davis Cup player in history on Friday when winning his 37th rubber against Tiafoe but the world number six was found wanting when, after winning the opening set on a tiebreak, he stood on the verge of a commanding lead.

He took a 6-1 lead in the second set tiebreak in superb fashion only to crumble under Querrey’s onslaught with the American world number 61 winning seven straight points.

“I just hung in there. After being 6-1 down in the tiebreak, I just played aggressively and from then on the pressure just builds,” said Querrey.

Cilic’s early dominance on the outdoor clay, cheered by an enthusiastic crowd in the Dalmatian resort, then evaporated as Querrey took the next two sets to win in three hours and eight minutes.

In Lille there was relief that the Croatians had won as it guaranteed the final would be a home tie for France.

Yannick Noah, who will be seeking a fourth win as French captain, will be wary of the Croatian firepower. He was captain two years ago when Cilic contributed all three points to the home side’s semi-final win in Zadar.

“That was kind of a bitter feeling for me because I felt we were really close and we went and lost it,” recalled Noah. “Now, with the chance of back-to-back wins, this is going to be an opportunity for us to go into the history books.”