ROSS Lyon has many famous sayings, but one of the Fremantle coach's personal favourites is that players write their own story.

On Saturday night, nobody should have been surprised that champion midfielder David Mundy scripted a fairytale for his 300th outing in purple.

Up until midway through the third quarter, it hadn't been Mundy's night against the Western Bulldogs.

DOCKERS DO IT FOR MUNDY Full match coverage and stats

Not through lack of trying, but the 33-year-old simply wasn't having the influence he would have wanted, despite a steady 11-disposal, two-clearance first half.

Maybe it was because of an emotionally draining week, which Mundy described as "overwhelming" as far back as Monday.

But the Fremantle veteran is a man for the big moment, and there never should have been any doubt he would leave his imprint on a marquee occasion.

WATCH Mundy puts on a clinic in his 300th

Nine minutes into the third quarter, Fremantle was wobbling and needed someone to steady the ship.

Red-hot favourites after a stunning upset win over Greater Western Sydney in Canberra, the home side couldn't shake the tenacious Bulldogs, who had clawed back from 13 points down at quarter-time to hit the front by seven.

Sensing the moment, Mundy went up a gear and straight-lined a ground ball at half-back, smashing into Mitch Wallis.

Only seconds later, he streamed through the centre square, getting on the end of Andrew Brayshaw's handball at 55m.

The crowd rose as Mundy cruised inside the arc in that typical long-legged loping style before chiselling a team-lifting major straight through the middle.

Teammates came from everywhere, and suddenly the 43,732-strong Purple Army was in full voice.

There was a second act and an encore still to come.

A crucial clearance in defence, followed by a crunching tackle on Jason Johannisen at half-forward, helped create Brandon Matera's go-ahead goal.

Shortly after, Mundy hit Jesse Hogan lace out inside 50, who failed to come to the party and hooked his set shot.

But then, in a fitting finish to a game-changing seven minutes, Mundy tested his ageing hamstrings with a 55m bomb that just cleared the line, much to the delight of his parents in the crowd, and set the Dockers on the road to a 19-point victory.

"Only just made the distance, so that was nice," a breathless Mundy told Channel Seven post-match, before typically deflecting attention to his teammates.

Mundy's third quarter was huge. He had eight disposals, three inside 50s and two tackles, turning the tide in a ferocious midfield battle.

A week after Adelaide's much-loved goalsneak Eddie Betts rose to the occasion and bagged six majors in game 300, Mundy ensured his milestone wouldn't end on a sour note.

He finished with 28 possessions, 11 contested, a game-high seven tackles, six clearances, six inside 50s (equal game-high), four centre clearances (equal game-high) and two majors.

David Mundy celebrates the win with an understated fist pump. Pic: AFL Photos

As the final siren sounded, Mundy celebrated with an understated fist pump, before savouring the adulation as he was chaired off the ground by Nat Fyfe and Alex Pearce through a guard of honour from both sides.

For a man who has shunned the limelight, it was a rare and deserved moment in the sun.

"It's been an emotional week, to be honest. I have never experienced the individual focus as I've felt this week," Mundy said.

"The love and admiration from the whole Fremantle faithful and guys at the club has been overwhelming.

"I'm glad I got through it and did my bit."

By the time the crowd had filtered out of Optus Stadium, about 20 of Mundy's friends, family and three young children joined him on the field to soak in the moment.

David Mundy's friends and family soak in the moment. Pic: AFL Photos

Only ex-teammate Matthew Pavlich before him had achieved the remarkable feat of 300 AFL games from a West Australian club.

Like Pavlich, Mundy possesses that rare ability to elevate in crucial moments that separates the elite from the rest, and there are no signs he is slowing down yet.

"He's not going to the end, he's bursting through the 300," Lyon said.

"It's one week at a time obviously, but I know he's keen to go on and we're keen for him to go on."