SAM Mayes had 13 touches to half-time in the SANFL game against North Adelaide at the muddy Prospect Oval when the call came to get to Adelaide Oval. He was to be the medical substitute to cover the late loss - in the warm-up - of experienced defender Hamish Hartlett (hip) for the AFL clash with Sydney.

Dylan Williams had managed just three kicks in three quarters of his challenging AFL debut that was highlighting just how steep the rise from the SANFL can be, even for a teenager floating on the buzz of kicking six goals six days earlier.

Destiny put together two players - probably two unsuspecting players - in a game needing a hero or two to decide an intense encounter that will mean more to Port Adelaide than just its 10th win of the home-and-away season and a return to the AFL top four ... by beating a top-eight rival.

Mayes was activated late in the last quarter, after key defender Trent McKenzie - who had been minding Sydney power forward Lance Franklin - had his left collarbone crunched in one of those dramatic head-down collisions for a loose ball with Sydney forward Will Hayward.

Williams, after being introduced to the big league with the huge shadow of Sydney co-captain and All-Australian Dane Rampe, was digging deep to put his mark on the game, either in search of an opportunist moment or in putting heat on Sydney defenders rebounding from the back 50-metre arc.

With less than five minutes to play - and Sydney leading by four points - a passage of play that was impossible to imagine just a few hours earlier changed the shape of a game, the AFL top eight and the commentary that comes with Port Adelaide's status in the premiership race.

Williams, just 19 (for a few more days), showed the calmness that was beyond more experienced AFL players when he patiently held his kick from the top of the 50-metre arc on the north-west of Adelaide Oval until there was at least a 50-50 option to consider.

That came from Mayes and team-mate Steven Motlop (who has been here before, particularly at this northern end of Adelaide Oval).

"Smart footballer," said Port Adelaide coach Ken Hinkley of Williams, his club's third pick (No.23) in the 2019 AFL national draft.

This time it was Mayes - the man who loaded up Robbie Gray for the match-winning goal after the siren against Carlton at the Gabba last season - who was the hero. That awkward, bouncing kick with so little time and very little room in which to work through can join in the book of famous, unorthodox shots at goal like the Angus Monfries' cracker that changed the outcome (in Port Adelaide's favour) the last Showdown played at Football Park in 2013.

Port Adelaide 73, Sydney 71 ... and with 1:57 left on the clock, lead ruckman Scott Lycett iced the game with Port Adelaide's 12th goal, almost in the same way Chad Wingard followed up Monfries' goal for the match-winner in Showdown XXXV at a West Lakes.

That day in 2013 gave credence to Hinkley's bold billboard promise at the start of the season - and the club's revival - that his team would "Never, ever give up".

Eight years later, this round 15 match - that was to be all about measuring Port Adelaide in top-eight battles (now 2-3 in 2021) - that mantra is about the character in Hinkley's team rather than a slogan for T-shirts.

"Our resilience is remarkable," says Hinkley.

This is the essence of this game that was starting to become a rerun of the double extra-time elimination final in 2017 against West Coast at Adelaide Oval - for untimely injuries and costly free kicks against Port Adelaide.

With 5:46 left on the clock it could have been easy to think destiny wanted to revisit that 2017 nightmare.

McKenzie was grimacing on the bench as the medicos checked his collarbone; key forward Charlie Dixon was limping around the centre square ("bashed up," said Hinkley) and captain Tom Jonas had gifted Franklin his fourth goal with a holding-the-ball free kick that became Sydney's last score and a four-point lead.

"We hung in there (when it could have been easy) to not keep at it," Hinkley said. "And we can be proud of that."

This time, Travis Boak decided there needed to be a different ending rather than another critical game slipping away by less than six points. His work in the last 10 minutes of this match defined Boak - yet again.

"That," said Sydney coach John Longmire of Boak, "is what good players do - they keep going for the whole game."

"Amazing," added Hinkley, "He worked, he willed himself into the game."

At each end of the field there was a significant sub-plot to a game that exceeded every pressure index at the average AFL game.

In defence, Aliir Aliir endured so much in his first battle against his former Sydney team-mates, in particular Will Hayward who was assigned the challenge - as Longmire put it - "of reducing Aliir's influence in the air". And Aliir - being resilient to the end - took the decisive intercept mark that cut off Sydney's last challenge.

In attack, Dixon defied tactics that at times put him against as many as four Sydney defenders in aerial contests. At half-time, one of the notable numbers on the Champion Data statistics was Port Adelaide making Dixon the target for seven of its forward sorties.

Predictable?

"That is what key forwards get - a lot of the ball sent their way," Hinkley said. "Even Franklin does at Sydney."

Should there be more targets, as noted in the premiership models of recent times?

"We're building that forward line to get growth in our three talls," answers Hinkley who is maintaining faith in the three-man model of Dixon, Todd Marshall and Mitch Georgiades. "In eight to 10 weeks, they will be better for the time they have together."

For the record - that other reliable barometer for Port Adelaide-Sydney games held true. Port Adelaide won the contested ball, 155-148.