Newport reached the Sky Bet League Two play-off final after a 5-4 aggregate win against Forest Green in a pulsating, topsy-turvy semi-final second leg at The innocent New Lawn.
Two goals in less than a minute from Ebou Adams and Aaron Collins wiped out Newport's first-leg lead early on, before Nicky Cadden's free-kick gave the hosts the lead in the tie for the first time.
A stunner from 42-year-old Kevin Ellison then pulled County level again and though it looked as though Joss Labadie's strike would send Michael Flynn's men to Wembley, former Newport frontman Jamille Matt popped up in the 87th minute to send the tie to extra-time.
As the rainy conditions began to take their toll in the added 30-minute period, penalties looked to be looming, particularly after Nicky Maynard sent a free header wide of the right-hand post, but the veteran striker had the final say one minute from time, when he latched onto a long ball and slid past Rovers goalkeeper Luke McGee.
As a result, Newport will face Morecambe in the League Two play-off final on Monday, May 31, after Derek Adams' men saw off Tranmere earlier on Sunday afternoon.
How Newport reached the League Two play-off final
In an interview with Sky Sports before kick-off, Forest Green chairman Dale Vince played down suggestions of an uphill battle, despite a 2-0 first-leg defeat at Rodney Parade on Tuesday night - and within 10 minutes of a wet and windy night in the Cotswolds, he was proved right.
Even though Newport sat tight to protect their aggregate lead in the opening exchanges, they were pegged back when Adams leapt well to meet a corner and glanced in a brilliant header.
Inside 60 seconds, the visitors were left shell-shocked as Collins - whose brother Lewis scored for Newport in the first leg - latched onto a sensational cross from Bailey Cargill and beat County goalkeeper Tom King with a first-time volley to match.
Newport battled back to dominate proceedings and went close when Mickey Demetriou nodded wide at the far post, though they were almost caught cold on the stroke of half-time when Collins' shot was deflected onto the crossbar.
But that's exactly what happened with 53 minutes on the clock, when Cadden lifted a free-kick high into the air that bypassed the crowd of bodies in the area, zipped off the surface inside the six-yard box and rippled the back of the net.
The drama didn't abate there. Having been on the pitch a matter of minutes, Ellison - the oldest player to ever feature in the EFL play-offs - silenced the home crowd when he latched onto Demetriou's knockdown 25 yards from goal, turned and curled an incredible effort into the top corner to level the tie on aggregate.
Four minutes later, fellow substitute Labadie swept in a cross from Ryan Haynes, but former Newport striker Matt - who made his first start since March 27 - forced the tie to extra-time when he struck from close range.
Questionable defending from Forest Green presented the unmarked Maynard with a chance to seal victory for the visitors, though he planted his header wide of the mark, before Josh Davison couldn't quite apply the finish when Jayden Richardson smashed the ball across the six-yard box.
But Maynard redeemed himself in the 119th minute when he latched onto a long ball forward, touched the ball past McGee and then slid home a winner that was met by a deafening silence.
What the managers said...
Forest Green interim manager Jimmy Ball: "We have got a lot of disappointed men in there who have literally given everything they could. As their interim manager, that's all I can ask for.
"I asked for a reaction, we got one; I asked for them to be brave, they were. I asked them to take risks and make sure when we left the pitch, we had no regrets. I don't think they do. They have got to have full hearts after that.
"Football is cruel. Maybe we just didn't have enough quality. It got a bit open and I wish we could've dominated the ball a bit better once we went two up and even three up, but we never really did and, unfortunately, we ran out of legs a little bit. No excuses, I hope you were entertained."
Newport's Michael Flynn: "It has been an absolute rollercoaster. First of all, I want to give praise to Forest Green, Jimmy and their team. The way they started the game was superb and a lot of credit needs to go to them. As an advert for League Two, I thought the game was absolutely outstanding. I'm absolutely over the moon.
"The conditions were the same for both teams. The pitch is lovely. We tried to play and as soon as the second goal went in, we actually woke up, which was very unlike us. We knew what to expect and the manner of the goals we conceded today, I'm not happy with and I have just told them that.
"I said to my assistant Wayne (Hatswell), 'Let's get Kev on; I'm telling you he will score.' He wasn't quite sure, but he did tell me Nicky Maynard was going to score the winner, so fair play! The subs had to come on and I have told them they are all part of what we are trying to achieve, even the boys who are not in the squad. They are all in it together and I'm very, very proud of them.
"It [the final] is going to be a very, very tough game. I said every game would be close in these play-offs because there wasn't much separating the teams. Derek Adams has done a fantastic job with Morecambe and it is a game I'm looking forward to. May the best team win and, hopefully, it's us this time."
Man of the match - Kevin Ellison
It was written in the stars. The oldest player to ever appear in the EFL play-offs rolled back the years and scored a wonderful goal to keep Newport in the tie, which they built upon to, ultimately, reach Wembley. There, Ellison will go face-to-face with his former boss Derek Adams - with whom he has a well-known feud - for a place in Sky Bet League One next season.
Newport progress to the Sky Bet League Two play-off final, which takes place at Wembley on Monday, May 31 at 3pm, while Forest Green will remain in the division for the 2021/22 season, which begins on Saturday, August 7.