Young AFL superstar Sam Darcy has taken a “season-defining” mark to save the Western Bulldogs from almost certain finals exclusion.

Needing to win to remain within one win of the top eight, the Dogs had almost secured victory over Melbourne on Sunday until their two-goal lead was cut to one with just under a minute left on the clock.

WATCH THE VIDEO ABOVE: Sam Darcy takes couragous mark to save the game for the Bulldogs.

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Bulldogs ruck Tim English kicked a high ball out of the next centre bounce stoppage with 47 seconds on the clock, with only a mark needed to all but secure the win.

Enter Darcy, who sprinted from about 20 metres away, running back with the flight of the ball to take one of the most courageous marks of the year.

“It’s a superb, Nick Riewoldt-type mark!” Brian Taylor exclaimed, referring to Riewoldt’s incredible 2004 grab against Sydney when he ran back with the flight of the ball in a similar fashion.

Riewoldt himself was there on Channel 7’s coverage to witness Darcy’s effort.

“Here’s where he comes from, it’s 20 metres away. Haven’t seen it from him before,” he said.

Taylor added: “If you don’t mind me saying Nick — I’d say it if he wasn’t here, but he happens to be here — that is so similar (to your mark). And what a moment to do it.”

Alister Nicholson called it a “season-defining moment for the Western Bulldogs right there”.

The Bulldogs’ finals hopes appeared in peril when Melbourne chased down a 21-point deficit to lead by 10 at three-quarter time.

But Luke Beveridge’s charges found an extra gear in the final term to prevail 15.15 (105) to 15.9 (99) in front of 34,733 fans at the MCG.

The Bulldogs (52 points) sit ninth, four points behind Gold Coast, Hawthorn and GWS, with home games against West Coast and Fremantle to come.

On Sunday, the Bulldogs led by five at quarter-time, 10 at half-time and 21 early in the third term.

But Jake Melksham put Melbourne in front late in the third quarter — a seven-goal term for the Demons.

Darcy restored the Bulldogs’ lead briefly before Gawn stood tall to put the Demons in front, then Christian Petracca extended the three-quarter time margin to 10.

The final quarter proved an arm wrestle with five lead changes, but the Bulldogs won out.

Ed Richards had 20 disposals and six clearances to half-time and finished with 31 and 14, while kicking two crucial final-quarter goals.

Marcus Bontempelli (33 disposals, seven clearances) and Bailey Dale (29 disposals) were also crucial.

With Darcy well held by veteran Demon Tom McDonald, Aaron Naughton (five goals) led the charge in attack.

Demons skipper Max Gawn (42 hitouts, 23 disposals) was superb all day, while Clayton Oliver (27 disposals) was busy.

Melbourne youngster Caleb Windsor (hamstring) limped off late while Bulldog Laitham Vandermeer was benched after a heavy landing.

- With AAP