USA fought back from the brink to defeat recent rivals Ukraine 2-1 in Budapest and defend their Junior Fed Cup by BNP Paribas title on a thrilling final day of action in Budapest.

The finalists duelled at both the 2016 and 2017 14-and-under World Junior Tennis championships, splitting the honours in Prostejov.

And following a high-quality week of tennis in Hungary, USA and Ukraine had to be separated by a match tie-break in the deciding doubles. Having saved a match point against Lyubov Kostenko and Dasha Lopatetskaya, Coco Gauff and Alexa Noel finally secured the victory to lift the prestigious Junior Fed Cup trophy for the Americans for a fifth time.

"It feels great that we've defended it. We were inches away from losing the title. My serve was just in (on Championship point). I'm just relieved I didn't have to serve a second serve then," Gauff said moments after the 5-7 6-4 11-9 triumph.

"We had to trust our games. In the first set we were just a little too passive and in the match tie-breaker we played super aggressive, which proved to be the difference in the match.

"I'm really proud of my team. We've overcome a lot this week. Me, Alexa and Connie (Ma) hadn't really spoken before this trip, so I think we make such a great team, constantly supporting each other no matter what the score.

"This has been such a long week. Alexa and I have had some long, tense battles. We might not have always played well, but I think we're champions because we fought harder."

Noel was part of the 2016 World Junior Tennis squad who fell to Ukraine in a doubles Championship tie-break and she was relieved to avoid a repeat defeat in Budapest.

"It's just been incredible to be a part of this week," stated the world No.10. "It's been a privilege to represent our country and we've all been so supportive of each other and that really helped us out the entire week."

Kostenko put in a ruthless display to open up proceedings 64 61 against Noel, which ramped up the pressure on Gauff to clinch victory in the second rubber.

Lopatetskaya inflicted a three-set loss on Gauff at the US Open earlier this month and it was another pulsating encounter in front of a packed crowd at the Hungarian National Tennis Centre.

"I knew we had to win otherwise we'd lost the trophy," said Gauff succinctly, having closed out an impressive 6-1 4-6 6-0 scoreline on Sunday afternoon.

"I was in the same situation against the same opponent last year in the Czech Republic, so I knew I had the ability to win again. I needed to stick to the game plan, stay positive and even though I lost a set, I think that was my best match by far from this tournament.

"I knew what I had to do, I knew her game really well. I couldn't beat myself up as in the past against her I've been pretty negative on myself and she's fed from that. I had some negative moments but even when I was down I shook it off and stayed pretty positive."

It was the same quartet of players from the opening two singles rubbers who graced the court in the doubles. Two high intensity sets were split before the trophy was clinched on a match tie-break.

Cheered on by ardent support, Gauff and Noel managed to overhaul 1-4 and 6-8 in the race to 10 points. Brave net play and piercing serves finally ended the Ukrainian resolve, igniting raucous celebrations on the clay.

Inspired by rapper Drake's song 'Back to Back', Team USA had successfully defended their crown with an astonishing comeback to the delight of their coach.

"It feels good. I guess we're just still on a high, soaking it in, but I'm very proud of the girls. Especially coming out here and winning that Championships breaker, it's certainly not easy and they played big," declared USA coach Erik Kortland.

"They showed so much heart, they put it all out there. I told them to enjoy the moment, we might not get a moment like this again and to keep fighting."

"They've learned to manage their expectations, which is huge. We had goals of displaying a good attitude and giving maximum effort, the girls really worked towards that, so I couldn't be more proud.

Meanwhile, Slovakia were rewarded for a strong week by collecting the bronze medal in a 2-0 victory over Russia in the third-place play-off.