Ladder leaders Melbourne have signalled their premiership intent with a hard-fought 26-16 victory over fellow contenders South Sydney.

Billed as a preview of a possible finals match-up next month, the Rabbitohs had their shot at upsetting the title favourites in a high-quality affair in Gosford.

The Storm stunned Souths by shooting out to a two-try advantage inside 12 minutes.

First it was a soft Jesse Bromwich try under the posts, before the Rabbitohs were opened up soon after and Justin Olam spun his way over.

Aided by eight consecutive penalties, the Rabbitohs soon recovered and earned one back before halftime with quick hands for Campbell Graham.

With Felise Kaufusi sin binned in the second half, Graham made it a double and set up a grandstand finish.

But the Storm drew on all their big-game experience, producing when it mattered for their 11th victory in their past 12 games.

It was usual suspects Cameron Smith and Cameron Munster who delivered in the clutch, combining to produce the go-ahead try in the 61st minute.

Munster beat four defenders in his decisive try.

The contest was seemingly over when Smith converted a penalty goal soon after to push out the score to 20-12 only for Graham to score this third, reducing the gap to four with six minutes to go.

Smith and Munster then combined again to put Brodie Croft over for the game-sealer, which now moves the Storm six points clear atop the league.

They are now all but assured of finishing with the minor premiership.

The Rabbitohs, meanwhile, remain in fourth place on 28 points – just two ahead of Manly and Parramatta with four games remaining in the regular season.

And they will be banking on the inclusions of Sam Burgess, Braidon Burns and George Burgess should the two heavyweights meet again in September.

Bennett had sprung a surprise change before kick-off by putting veteran John Sutton on the bench for the first time in 12 years.