Melbourne have officially sealed the minor premiership with fill-in half Brodie Croft firing them to a 44-12 NRL win over Newcastle on Saturday.

Stepping into the shoes of rested Queensland and Australian playmaker Cooper Cronk, 20-year-old Croft was a standout, scoring three tries and setting up another two in front of 16,001 fans at McDonald Jones Stadium.

The Storm moved to 40 points, six in front of second-placed Brisbane, locking up first spot and assuring they will lift the JJ Giltinan Shield.

It broke Newcastle’s three-game winning streak and while Nathan Brown’s side have earned plenty of admirers recently, the 16th placed Knights were outclassed by the title favourites.

The Knights also have a concern over skipper Sione Mata’utia, who has suffered several concussions over the last two seasons, after he left the field for a head injury assessment in the 30th minute and did not return.

As well, in-form five-eighth Brock Lamb left the field late in the game after struggling with a knee injury for 50 minutes.

With Cronk to leave the Storm and perhaps retire at the conclusion of 2017, Croft’s performance gave the Melbourne faithful plenty of hope they can be competitive for years to come.

When Jesse Bromwich was sin-binned for a professional foul, the Knights took a shock early lead with Lamb setting up Lachlan Fitzgibbon close to the line.

However the Storm soon took back the ascendancy with Croft kicking for Curtis Scott to score before crossing himself to make it 16-6 at the break.

Croft extended his side’s lead nine minutes after the resumption with a sensational individual effort from 30 metres out.

The Storm’s performance was far from complete with the Knights scoring through Joe Wardle to get back within 10 points however the visitors closed out the game with Will Chambers crossing before Croft got his hat-trick.