STEPHEN Hill appears highly unlikely to line up in next week's huge Western Derby, although Fremantle coach Ross Lyon remains "hopeful" the star midfielder hasn't torn a hamstring.

Hill pulled up short as he ran along the boundary during the frantic final quarter against North Melbourne but, despite appearing to have strained his hamstring, he stayed on the field for several minutes.

The 26-year-old eventually limped to the bench and was kept off for the dying stages of the Dockers' thrilling five-point win over the Roos at Domain Stadium.

Full match coverage and stats 

Speaking post-match, Lyon said Hill had hamstring tightness and didn't rule him out of the Derby next Saturday night.

"I'm hopeful, no one's told me anything other than that," Lyon said.

The Dockers snatched a nail-biting win on Saturday night to improve to a 3-2 record, a week after Cam McCarthy's toe poke clinched a thriller against Melbourne at the MCG.

Five talking points: Fremantle v North Melbourne

This time it was fellow recruit Shane Kersten – maligned early in the season – who stood up with a brilliant snap that bounced through to put Freo ahead in the final minute. 

"We never saw him under pressure, that's external pressure," Lyon said of the former Cats forward. 

"Ultimately, we would like kicks, marks, handballs and goals. But we see around the competition there's more than that. 

"You've got to work collectively and Shane was buying-in and preparing really well.

"He'll have his ups-and-downs, but we're really pleased."

WATCH: The last two minutes

Fremantle has come from behind in each of their three victories and the Dockers are building self-belief they can win from anywhere. 

They had to secure the win over the Roos the hard way after conceding seven unanswered goals between the first and third terms. 

Freo trailed by 29 points early in the third quarter, and were on the backfoot for most of the match against the still winless visitors. 

WATCH: Ross Lyon's full post-match press conference

"We knew they would be really formidable and fierce, and at 0-4 (now 0-5) it's desperation time," Lyon said. 

"With a young group it's an insidious creep that mental game (in terms of complacency), and that was always a concern (for us). 

"I thought we started OK and then where our experience was at times we got obliterated around the ball in the second quarter. 

"The clearances, they just annihilated us.

"I know the crowd was roaring about umpires and all that, but you make your own luck.

"They were harder at it and striking at the ball.

"We thought we were close enough (at half-time to think we could) dig in here, and I wasn't really worried about the scoreboard, it was more our mental toughness to get going again.

"I thought we responded … and in the end it was quite thrilling."