MATTHEW Primus was so much "in the zone" he had completely tuned out of the real world. The Port Adelaide ruckman and future captain drove to Football Park at West Lakes unaware - such was his total focus - that the game was uncertain to be played.

August 31, 1997. That Sunday morning the world was dealing with the death of Princess Diana in a car crash in Paris.

Primus was only thinking of St Kilda and the challenge of countering Lazar Vidovic, who was - unbeknown to him at the time - about to play his last AFL game with a serious knee injury to force him into retirement.

"Princess Diana? I did not know," says Primus. "All I had on my mind was playing St Kilda ... I was totally tuned into a game that could have had us qualify for our first AFL finals series in our first year. I did have a bit on my mind ..."

And it remains there, 28 years later as Port Adelaide prepares to host St Kilda in the club's dedicated "Retro Round" with a lightning jumper from 2004 when the clubs met in an epic preliminary final at West Lakes and had dramatic encounters at York Park in Launceston.

"I do remember that game in 1997; I remember it quite well," says Primus, now coaching Queensland club Southport in the VFL. "But anything else that happened that day did not register at the time. I was so tuned into what we had to do that day at Football Park."

August 31, 1997 was to be no ordinary Sunday for either the Port Adelaide or St Kilda football clubs. The match had been moved - with the AFL agreeing to a media campaign for a stand-alone match with live national television coverage - to the twilight hour. But the day had started with no-one sure any AFL game would be played while the death of Princess Di left the world in shock. The crowd - 38,589 - arrived at West Lakes in a mood that contrasted the usual excitement generated at football grounds.

Port Adelaide started the weekend in ninth spot, tipped out of the top eight by Brisbane on percentage (107.7 to 93.1). Result by result fell into Port Adelaide's favour that weekend.

First, Brisbane lost to West Coast by 39 points at the WACA Ground in Perth in Friday night football.

On Saturday, Carlton lost to Richmond by two points at home at Princes Park. Then Fremantle fell to the Western Bulldogs at Waverley Park in Melbourne by 18 points. The path was clear for Port Adelaide.

The equation was perfectly simple - beat St Kilda and Port Adelaide would take eighth spot with an 11-1-10 win-draw-loss record, qualifying for finals in its inaugural season in the AFL.

"Destiny was in our hands," says Primus. "We all knew that."

Port Adelaide had last sat in the top eight - equal fifth to be precise - at the end of round 18 when it had the same win-loss count as Brisbane, North Melbourne, West Coast and the Western Bulldogs. It then took an 85-point belting from Geelong at Kardinia Park, lost the second Showdown by seven points after commanding the first three terms of the derby, drew with Brisbane at the Gabba and was battered by Richmond at the MCG by 85 points.

And confidence - and ambition - was still high in the team.

"Jack (senior coach John Cahill) was great all year in keeping us motivated," said Primus. "We also had a good list - a great mix of mature players and young talent. The club certainly did its homework when it put that inaugural squad together.

"And there was belief. That Port Adelaide belief. We know the club exists to win premierships. That is going to be a bit hard to do in your first season. But you can have belief - and Port Adelaide had that drive to succeed constantly reinforced by what John Cahill, Mark Williams and Greg Phillips were saying to us.

"There was a constant theme. If we played a bad game we were told it was not good enough. If we won, we were challenged to go again for the next win. There was this never-ending demand to do better ... to be the best."

Port Adelaide had faced St Kilda in round seven at Waverley Park while the Victorian club was rising from bottom after a 1-4 start that contradicted the promise of eventually winning its second VFL-AFL minor premiership.

"No-one expected us to win - at best the predictions were we would win just two games, if any at all," recalls Primus. "But we went into that game with the excitement of qualifying for finals - in our first year.

"I never felt the year was getting away from us. That first game - with the loss to Collingwood at the MCG - was a slap in the face. But we kept at it. We scored our first win (against Geelong). We won the first Showdown. We knew we could compete in the AFL. The results were telling everyone what we were about as a team - we wanted to win.

"It had been a long year. But we started that last game with so much energy. We were certainly motivated. And we should have been further in front at half-time (than one point, 7.8 to 8.1). We burned so many opportunities. We had doubled their shots on goal.

"We went into the rooms at half-time with energy and belief. The belief was amazing. We knew we were playing for finals. We were playing good football. We were taking the game on. And we were blowing our chances with our goalkicking (9.11 to 11.5 at the last change).

"And then St Kilda had its big boys - like Robert Harvey - take the game away from us. It was a pretty good St Kilda side; good enough to play in the grand final that year."

With its own inaccuracy - 6.10 in the last term - St Kilda claimed a 33-point win that was crowned with the club's first AFL minor premiership and second league award after the 1965 triumph.

Port Adelaide finished ninth, missing eighth spot to Brisbane by percentage. It was an extraordinary start to the national journey. From the 21 who played that closer in 1997, five survived for the premiership triumph in 2004 - Peter Burgoyne, Roger James, Brendon Lade, captain Gavin Wanganeen and 1997 Rising Star winner Michael Wilson. Primus and midfielder Josh Francou remained on the list but were sidelined by knee injuries in 2004.

The Port Adelaide-St Kilda rivalry has extraordinary moments across 37 AFL games that have spanned the globe to the now bulldozed Football Park and Waverley Park, Tasmania where Port Adelaide has a 3-1 record against St Kilda, China and now either Adelaide Oval or the Docklands in Melbourne.

There is the 2004 preliminary final at Football Park with Gavin Wanganeen's remarkable match-winning goal from the apex of a 50-metre arc - and Robbie Gray doing the same from a boundary throw-in tap from Patrick Ryder at Adelaide Oval in 2017.

And the past five matches between the clubs have been decided by two, 10, seven, one and 13 points.