Brisbane have overcome a perplexing refereeing decision to defeat St George Illawarra 30-22 in Friday night’s crucial NRL clash.

The Broncos, leading by 20 points after a Ben Hunt masterclass in the first half, were left stunned when Matt Gillett was sinbinned for a professional foul 54 minutes into the contest.

Gillett had tackled Dragons fullback Gerard Beale following a 70m break by Benji Marshall off a quick tap.

Referee Ben Cummins deemed the Queensland representative to be offside despite the fact Marshall’s run should have been more than long enough to put everyone onside.

The Dragons made the most of the lucky break, running in two tries while Gillett was off the field and a third two tackles after he’d returned to reduce the margin to just two points.

Gillett then steadied the ship for the Broncos, crashing over with eight to go to seal the Broncos win – their third in a row at home and eighth-straight against the Dragons.

The Broncos forward said on Channel Nine following the match that Cummins had apologised to him after he came back on.

The controversy overshadowed a cracking contest, where Broncos halfback Hunt scored a first-half double and set up another to have the home team leading 24-4 at the break.

The victory ensures the Broncos head to Melbourne next week knowing a win will almost certainly seal a finals berth.

The Dragons are unlikely to make the finals due to their poor for-and-against and will also sweat on the fitness of captain Ben Creagh for next week’s trip to Newcastle after he left the match in the first half with an ankle injury.