When Catalans Dragons walk out in their first Super League Grand Final on Saturday evening, those who have been on the French club’s journey since the beginning will perhaps allow themselves a moment to reflect. Every sporting story has a pivotal moment and for Catalans, who are on the verge of creating yet more rugby league history this weekend, that came almost four years ago to the day.

“I was numb,” says Alex Chan, the club’s chief executive, recalling his emotions from the 2017 Million Pound Game. “I remember everything about it because I knew the consequences if it had gone wrong.” It had been another disappointing season for Catalans, but this time the Dragons were in real danger of relegation from Super League.

Related: Catalans Dragons blast past Hull KR and into their first Super League Grand Final

Trailing Leigh at half-time in the play-off to determine which side would drop into the Championship, for a moment the sport’s last great hope of expansion looked to be about to collapse. A sport confined to its northern heartlands was about to lose its bastion of possibility in France.

However, that day ended in relief. Catalans battled back to beat Leigh, securing their place in Super League. Then, just eight months later, they lifted the Challenge Cup at Wembley and, since that day, they have not looked back. But for club stalwarts such as Chan, a Grand Final debut on Saturday has been years in the making.

Three months before that Million Pound Game, Catalans had appointed the former England coach Steve McNamara as head coach. Tasked with keeping the Dragons in Super League, he was already looking further ahead. “It wasn’t in the best spot when I got there,” McNamara recalls. “I didn’t ask too many questions, simply because I didn’t want to know the answers. Otherwise, I wouldn’t have taken the job. But I knew there was potential given the passion the people of Perpignan have for rugby league.”

McNamara had inherited a club with deep-rooted culture issues, dating back to the launch of Les Dracs in 2006. “This is clearly a superb place to live, work and bring your family to experience,” he says. “But you’re here to work, and if you’re doing well then you enjoy the lifestyle. For a long time it was the other way around for the overseas players who came.

“Reputations stick. Perceptions stick. We’ve had to work incredibly hard to convince people that it isn’t how it used to be, and we’re not flooding the beach bars in June and July instead of working hard and knuckling down. That was one of the first things we had to tackle, and those changes don’t happen overnight.”

Slowly but surely, McNamara’s Catalans eroded the notion that a contract in Perpignan doubled up as a holiday or, if you were arriving from the southern hemisphere, a place to wind down your playing career with a lucrative pay cheque. Signings such as Sam and Joel Tomkins, plus established Super League stars such as Michael McIlorum, have gradually shifted the mentality in the south of France.

“The appetite in this region for rugby league is huge,” says Joel Tomkins. “Every village and town has got a club, it’s frighteningly similar to places like Wigan and St Helens in England.” The unwavering support of the owner, Bernard Guasch, who secured Catalans’ entry to Super League in 2007, has been vital.

But the Dragons limped along in relative mediocrity, with a raft of big-name overseas signings in the autumn of their career failing to deliver: things needed to change. McNamara’s arrival heralded a fresh approach and, less than a year later, they answered their critics in the summer of 2018 by beating Warrington at Wembley.

“We’d been to the Challenge Cup final in 2007 but lost, and before three years ago we were looked upon as a bit of a bridesmaid,” Chan says. “That day changed rugby league in the UK. My goal has always been to take the game away from just the heartlands and strengthen it. It exploded over here in France after winning the cup, and the snowball effect has been huge.”

With an increased investment and focus into developing young French talent – such as Arthur Mourgue, the livewire full-back or hooker who will feature at Old Trafford – plus the success of Toulouse, who are overwhelming favourites to join Catalans in Super League in 2022, French rugby league is thriving.

Catalans finishing top of Super League for the first time was one thing, but a sold-out crowd roaring them to victory against Hull KR last week to secure a maiden Old Trafford appearance is another. Victory in the game’s showpiece stands to elevate its appeal beyond its heartlands in the northern hemisphere.

Related: St Helens sweep Leeds aside to book final date with Catalans

“There are English rugby league clubs who’ve been around for decades who haven’t had the success Catalans have had,” Chan insists. “This could change the game as we know it. If we can take the league title away from the so-called heartlands and back to Perpignan, I can’t put into words what that could do for rugby league all across the world.”

McNamara, whose only previous Grand Final appearance was in 1999 as a player with Bradford Bulls, agrees. “Wembley put us on the map. The interest has gone to another level all across France in recent weeks, though. This club is only 16 years in to its story. We have an infrastructure as good as any in Super League.

“We have young players as good as any in Super League. Four years ago feels a lifetime ago in some respects, but we’ve worked so hard to reach this point. It’s an historic moment for the sport, not just for Catalans Dragons. I’m glad I didn’t ask those questions of the board four years ago but now, we’ve got a chance to do something that could change the sport forever. It’s an honour to be part of it.”