It perhaps seemed like a chore to the players at the time. A defensive drill the Sharks squad would do over and over again after every single training session.

They'd simulate a scenario where six defenders would have to repel 13 players for a complete set.

So when they needed it most, in the dying seconds of the grand final against Melbourne grimly defending a two-point lead in search of their first premiership, the composure needed to do so was a habit.

"It reminds me exactly of training watching it back now. If we hadn't have played those games afterward, we might not have got it done," Lewis said.

"The coaching staff came up with that to make sure we turned up for each other. It doesn't matter if you're on the right or the left, you have to go over if you can see something happening and make that extra effort.

"We'd sprint to the right, to the left and form a line. Melbourne had to go from one side of the field to the other, but we wouldn't be denied.

"I do put it back down to that training set, that game we'd play after every session."

Cronulla hooker Mick Ennis won his sole premiership that night. Sharks legend Paul Gallen, too.

Storm centre Will Chambers could have passed to an unmarked Cooper Cronk to set up a late matchwinner, while a couple of other chances also went begging.

But Ennis, now a respected analyst on Fox League's coverage, backed Lewis' claims that Cronulla's late scramble defence deserves more credit.

"We did a lot of practice on it. It was a big area we'd spoken about being one of the trademarks of the club, to turn up for your mate no matter what the situation," he said.

"A lot of the focus has always been on what could have been for Melbourne. But the sea of Cronulla jerseys that came from everywhere at the end, it was what we were about all season with that never say die attitude.

"It would have been heartbreaking if we'd lost that, I tell ya. Boy oh boy."

Cronulla's only premiership in 53 years continued a fairy tale run of grand finals.

After South Sydney broke a 43-year title drought in 2014, Johnathan Thurston's Cowboys produced the greatest finish in grand final history 12 months later.

Brisbane needed just one more tackle to secure victory, but a Michael Morgan flick pass put winger Kyle Feldt over to level the scores after the full time siren.

Thurston's sideline conversion agonisingly hit the post. But after Bronco Ben Hunt dropped the ball from the kick off in golden point, 'JT' made no mistake with his field goal attempt to bring the premiership to Townsville for the first time.

After Leicester City shocked the world by winning the Premier League title and AFL's Western Bulldogs claimed the first premiership since 1954 the day before, the Sharks hoped there was one 2016 Cinderella story left.

There was. But the foundation for their pleasure was laid by the pain of an "embarrassing" night in Townsville 12 months earlier.

The legitimate mutual dislike between Melbourne and Cronulla is well documented. But the Sharks' rivalry with the Cowboys was almost as significant.

In 2015 the Sharks players were a shattered, inconsolable group after North Queensland hammered them 39-0 in the second week of finals.

It was that hurt, that utter humiliation, that fuelled their 2016 premiership run which featured a remarkable 15 straight wins midway through the year.

"That night I was burning, and I remember looking around the room and realising we still had the same side for the next year," Lewis said.

"The look in everyone's eyes was one where you could sense it was going to be a big off season, and something special was going to happen in 2016.

"At the time Gal stepped up and said 'boys, we don't know if we'll get another chance to play in a game like this. You have to appreciate the opportunities you have and not take it for granted, but we have to work harder if we want to get back next year."

Ennis said responding positively to that experience was vital in going all the way the following year.

"There's getting beaten, but getting flogged in a semi final was an awful feeling," Ennis said.

"That night was painful, that night in Townsville. You're so far from home and your season comes to an abrupt halt.

"Looking back in hindsight that night was a big cornerstone in how we prepared in 2016, because it just burnt so many of our blokes over pre season."

Ennis admits the Sharks "probably put everything in jeopardy" after losing four of their last five regular season games to drop out of the top two, forcing them to head to Canberra for week one of finals.

The Raiders had won ten straight games, and Cronulla was without an injured Gallen. Wade Graham also went off concussed early, but the Sharks still prevailed to set up a preliminary final date with North Queensland.

Although now on the Raiders' coaching staff, Ennis became public enemy number one in Canberra after mocking their fans with a rendition of the 'Viking Clap', a pre-game ritual they began that year.

"That's without doubt one of the best wins of my career. There was so much against us, the Raiders had won ten or 11 straight, GIO (Stadium) was a brutal and hostile environment," he said.

"The moment we to on the bus there was just a really special vibe about where we were going."

Sharks coach Shane Flanagan had the easiest job in Australia motivating his team for the preliminary final against North Queensland.

Still seething from the lesson they copped from Thurston's men a year earlier, the Sharks weren't about to let history repeat.

"No one was going to beat us that night and when we knew we were playing North Queensland we were going out to hurt," Lewis said.

"Our whole week was talking about hurting every one of those players. That's the way you've got to play the game and everyone bought into it."

Ennis added: "There was plenty of motivation in our group to return serve and we got to do that at a Sydney Football Stadium that was just packed to the rafters with Cronulla fans daring to dream."

"DON'T worry, 'Groover'. We've got this."

Lewis and Ennis were room mates. They'd sit up the front together on the team bus, and grand final day was no different.

After being "physically and verbally" dominated by Melbourne in a 26-6 final round loss at AAMI Park, Ennis was nervous.

But Lewis, who would go on to claim the Clive Churchill Medal, soon settled his good mate.

"Lewy put his hand on my leg and he said 'are you alright mate?'," Ennis said.

"Being the last game of my career, I started to get a bit emotional. Gal got on the bus and as much as I wanted to win one (premiership), I wanted to win one for him too.

"Lewy always called people 'Groover'. He said 'don't worry Groover, we'll be back here in two hours after we win this bastard.'

"From there everything started to slow down and I thought 'you know what, we're on a good thing there.

"There was something there during the week that we never questioned we were gong to win it. That's not being arrogant or disrespectful to Melbourne. I just felt like we were going to win the game."

The Sharks led 8-0 at halftime, but tries to Jesse Bromwich and Will Chambers gave the Storm a 12-8 lead.

With less than ten minutes left, Sharks prop Andrew Fifita scored a famous try when he muscled his way through four tacklers to get the ball down.

"It made the victory that much sweeter, how hard we had to fight to win it. Those dying moments felt like an age, it was bloody special to see no time left on the scoreboard," Ennis said.

Some normality has since been restored with the Roosters claiming the past two premierships after Melbourne's triumph in 2017.

Lewis believes it will be tough to emulate the romantic story lines the deciders from 2014 to 2016 offered up.

"I just don't see how grand finals get any better than those three years," he said.

"The next few days after our win was a great experience doing fan days, we went to Northies and we were crowd surfing to go to the toilet.

"I'd love to have been a fly on the wall at Northies or the Leagues Club when the siren went.

"You'd just love to feel the emotions and feelings the fans had when they knew we'd won it. It gives me goosebumps just thinking about it.

"Winning a grand final is the hardest thing to do, you'd hate to see someone like Gallen or JT play their whole career and not get a premiership.

"It's amazing to give guys like that the opportunity to leave the game with a ring on their finger."