NO CHANCE.

You could be forgiven for thinking that's what Essendon had when Tom Bellchambers limped from the field with just minutes remaining in the third quarter on Thursday night.

The Bombers were trailing, and with the deficit growing the odds were stacked against them already. Losing Bellchambers for the remainder of the match was meant to be a bitter blow.

BOMBERS BY A FINGERNAIL Full match coverage and stats

Little did anyone know such a moment would lead to a game-changing move.

Coaching from the bench, the under-pressure John Worsfold was forced to flip the magnets.

Cale Hooker had to help Shaun McKernan in the ruck. And when the roles reversed, he had to anchor Essendon as its main forward target. That in itself changed the game.

Having kicked six goals for the entirety of the first three quarters, all of a sudden Hooker's positional change led to six Essendon goals in the space of just 24 minutes.

"It was out of necessity," Worsfold said after the match.

"We had a few options that we weighed up, but talking to (assistant coaches) Mark Harvey and Hayden Skipworth about the best way to cover in the ruck … they felt we could cover if we took (Hooker) out of the backline and played him forward for short periods.

"They planned it out well, they knew how they were going to cover it and what it meant for us, so we went ahead with it.

"It was the coaches getting together, collaborating between lines and making sure we could get the result we were looking for both defensively and offensively."

While Worsfold was reluctant to take take credit for this one, those with long memories will recall Woosha's signature move in the mid-2000s was to shuffle swingman Adam Hunter forward (which was remarkably successful for West Coast in its 2005-06 glory days).

WATCH The thrilling final two minutes

Up until that point, Greater Western Sydney was dominating. The ball was entrenched inside its forward half, its midfield was on top and the lead was set to balloon to 19 points.

That's not to say Bellchambers wasn't having an impact. It could be argued he was among Essendon's best players, limiting Shane Mumford in the air and winning plenty of it himself.

But Hooker's arrival gave them what they had lacked all night – a potent scoring option.

While the Bombers' midfield – led by Zach Merrett and Dyson Heppell – summoned something special having appeared all night as though it would be overrun by the likes of Josh Kelly and Stephen Coniglio, it was the options forward of centre that were limited.

Enter Hooker: The 'break glass in case of emergency' forward.

Having kicked 41 goals back in 2017, Hooker hasn't been used consistently forward since. After his final-quarter heroics at Marvel Stadium, he might be again soon.

Within an instant, he was at the heart of every major contest. He marked strongly on the lead and, when he didn't, he crashed every other pack. All of a sudden, he was the man.

McKernan wasn't playing a bad supporting role, either.

Having been impressive throughout the match, he monstered Adam Tomlinson when Mumford was off the field at a crucial point and helped the Dons gain the ascendency.

With that momentum, a significant Giants lead was quickly whittled away.

'WE'RE STILL IN THIS' The message on the bench that gave Bombers belief

Setting up nicely behind the ball – a tactic Worsfold conceded he pinched from West Coast's dominant performance last week – Essendon ensured repeat entries piled on the pressure.

And, when the game was there to be won, it had the match-winners ready to strike.

It was fitting that when Jeremy Finlayson reclaimed the lead for the visitors deep in the last quarter, it was McKernan and Hooker who collectively dragged the Bombers back into it.

An Essendon entry was kicked to Hooker. With strong hands he marked, with even quicker hands he dished the ball to McKernan. From 50m out, the back-up ruck levelled the scores.

Time ticked away. From this point, it was surely next score wins.

And when Conor McKenna provided a deep kick inside 50, you knew who would be there.

Outleaping his opponent, Hooker marked at the top of the square. With mere seconds remaining, his kick was elementary. His heroics kept the Bombers' season alive.