Sydney have opened their AFL season with a 12-point victory over Essendon after a dramatic last-quarter fightback at ANZ Stadium.

Down 41 points late in the third term, the Swans kicked eight unanswered goals on Saturday to beat a spent Bombers outfit 10.12 (72) to 9.6 (60) in driving rain.

Superstar forward Lance Franklin broke the deadlock with just minutes to spare, but it was debutant Isaac Heeney who sealed the victory with a maiden goal in front of a rapturous 23,774 fans.

It ended what had been a good news week for the Bombers after 34 current and former players were cleared by the league’s anti-doping tribunal of taking banned substances.

Coach James Hird didn’t know if his men could last the distance, given 13 of them hadn’t played a single pre-season match while serving provisional suspensions.

In the end, more than two hours of footy and a fitter Swans outfit proved too much.

The Bombers appeared to have the Swans in a headlock early on, slotting four goals to none in the first term for a 26-point lead.

They dominated across the field, allowing Sydney inside their 50 just five times – their fewest entries in a quarter since mid-2013.

The early loss of midfielder David Myers with an injured shoulder proved the only low point in an otherwise impressive start to 2015 for the Bombers.

Myers was subbed out just three minutes in after an accidental collision with Kurt Tippett.

The one-way traffic continued into the second quarter, with Sydney unable to boot their first goal until 18 minutes in through Craig Bird.

Despite spending more time in their forward 50, the notoriously slow starters failed to get another major in the half.

With poor deliveries and a disorganised forward line, big men Tippett, Franklin and Mike Pyke had just six touches between them.

But Franklin’s goal six minutes into the final term sparked the comeback, marking the Swans’ fifth win in a row over Essendon in what was coach John Longmire’s 100th game at the helm.

On the downside, the Swans lost workhorse Luke Parker after a sickening collision with Franklin in the opening minutes of the final quarter.

Parker had led the tally with 35 disposals and 10 clearances before being taken off on the medicab.

Former Western Bulldog Adam Cooney was a standout for the Bombers, kicking three goals on debut.