‘Insane’: Inside wild Knights celebrations as sent off star leads way, coach delivers ultimate praise

"Holy s***. Holy s***."

Those were the only words Kalyn Ponga could muster as the Knights captain walked off the field and down into the tunnel after watching his side complete one of the most remarkable turnarounds in NRL history.

Twelve months after finishing with the wooden spoon, the Knights are now heading to the grand final for the first time in 25 years after a remarkable preliminary final victory over Penrith on Sunday.

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As Ponga and his teammates made their way through the tunnel, the enormity of what Newcastle had just achieved was beginning to sink in.

"It's still pretty surreal to be honest. It's not really sunk in yet," Knights winger Dominic Young told foxsports.com.au.

"We're just happy and excited, especially given the circumstances. It was a massive, massive effort.

"I'm speechless. It didn't feel real. Ten minutes to go, you look at the clock and you're up and know you're so close and when it finally ends, I can't really describe it."

For head coach Justin Holbrook, there was no need to overthink what his side had just achieved - coming from behind with only 12 men to pull off the remarkable triumph.

"I just want to start by saying that is the best win in the history of rugby league," he said in his post-match address to the players before praising Sandon Smith.

Starting the season on the interchange bench, the Knights halfback had just produced the best match of his young career.

Taking on a Panthers outfit playing in their seventh consecutive preliminary final, Smith scored twice to swing the momentum of the match, including an 80-metre intercept in the final seconds to seal the Knights' place in the grand final.

"I can't believe what's going on," Smith was heard saying.

"F*** let's get it next week. I can't wait."

Smith's final try made it all too real for Harrison Graham.

"To be honest, I can't really explain it. It was insane," he said.

"When Sandon ran away for that last try, I just collapsed.

"It's unreal. We live another week and we're into a grand final.

"I am lost for words. I wasn't here last year, but the boys last year obviously struggled a bit and the turnaround from the club (has been amazing). All the fans that turned up today are just unreal."

In the stands, former Knights captain and legend Kurt Gidley struggled to contain his tears as he watched his former side pull off the unimaginable

"Most courageous win I've ever seen!!!" Gidley posted.

It triggered an array of messages that quickly flooded in.

"F****** UNBELIEVABLE GIDS…What an effort!! Brings back great memories! Gonna be an unreal week in Newy," John Morris, a member of the 2001 premiership-winning squad and Gidley's former teammate, added.

"How f****** good," Beau Ryan said.

"F**** awesome scenes," Cooper Johns posted.

Meanwhile, two-time premiership winner Andrew Johns was almost left speechless as he watched his former club survive the majority of the contest with only 12 men on the field.

"What an effort. 12 men. The reaction of the players - I can imagine what it means to people back home," Johns said on Channel Nine.

"I can't believe it. We've been up against it all year, today was no different.

"A man down for the whole second half, and I'm just so proud of the group ... our region back home, all the fans here, they deserve this."

Back inside the sheds, there was only one thing left to do.

Celebrate.

Injured halfback Dylan Brown was seen with his family as players embraced one another and the dressing room descended into chaos.

Cody Hopwood was among those soaking up the moment alongside rookies Diesel Hagan and Toby Winter.

Only 17 matches into his NRL career, the 20-year-old graduated high school less than two years ago.

"I'm lost for words. I can't describe this feeling. It's honestly the best feeling in the world. I can't believe it," he told foxsports.com.au.

"If someone said this was going to happen in two years, I would have told them to get out of my sight.

"I'm very privileged to be in the position I am and understand the responsibility that it comes with and how we can make the community feel.

"It's so pleasing that we're doing that at the moment."

Backrower Jermaine McEwen summed up exactly what the moment meant to the playing group.

"Pretty happy and proud of the boys for their effort tonight," he told foxsports.com.au.

"To do it for the city, for the people. That's who we do it for and excited to get back home and feel the spirit over there.

"This is something you watch. You build all the dark places you go in pre-season and the sore bodies and the sweat and tears that go into this.

"This is why you do it and we're just so happy and so grateful.

"The lord's the one doing his thing with us and we're so happy we can go out there next week and have an opportunity to take out (the premiership)."

Teammate Greg Marzhew added, "I was in shock to be honest and I'm still in shock.

"To do it for our fans and seeing where they had to ride the lows with us last year when we were at the bottom of the ladder, it's good to kind of switch it up for them."

Eventually the wild celebrations reached their crescendo.

Phoenix Crossland - who was rubbed out of the match for a hip-drop tackle on Nathan Cleary - led the Knights through the team song with his boots in his hands, pounding down on a Jim Beam esky.

The players screamed at the top of their lungs as they sang, with family members joining in on the celebrations behind them

After everything they've been through, the Knights are now on the verge of making history.

A win against the Sydney Roosters would mark the first time in the NRL era a team has gone from last place to premiers in successive seasons, while the Knights could also be the first team to win the premiership from outside the top four

"It is unbelievable, I don't know what to say," club great and Knights premiership-winner Matty Johns said on Fox League, wiping away tears.

"I am just so happy for all the fans and all the people who have had to put up with a lot of shit for years to get back to where they are now.

"Nothing was straightforward today. There was the breakdown on the lines for fans (travelling), cars were backed up on the M1 ... but that didn't stop them.

"When you run to a field like that and look up to see all those fans, you don't leave the field defeated. If not for the fans, they don't win today."