Two first-half tries to Joey Leilua and an inspired defensive display has helped Canberra to a 22-8 win over Melbourne to announce themselves as a genuine NRL premiership threat.

One week after handing Cronulla their first loss since March, the Raiders on Monday night became just the second team in 30 years to beat the competition leaders in back-to-back games.

In front of a 15,707 fans at GIO Stadium, the Raiders claimed arguably their best win for the year with their defence turning the Storm away 51 times inside their own 20m zone.

In contrast, Canberra had just 16 possessions in the opposition red zone.

But that was all the home side needed, crossing for three tries to become the first team to score more than 20 points against the best defensive team in the competition this season.

The win lifts Canberra back to third spot on the ladder, ramping up expectations of a title push while the Storm remain in first with three games remaining in the regular season.

Canberra stunned the visitors with a try in the first set of the match, Leilua putting Blake Austin into the backfield before backing up to score the quickest try of the season.

Storm halfback Cooper Cronk replied when he ran the ball in the 17th minute, however Leilua returned by ploughing through three defenders seven minutes later.

Jarrod Croker’s penalty goal gave Canberra a six-point advantage at halftime before Shannon Boyd crashed through under the posts in the 54th minute and Croker sealed the win with a 76th minute penalty goal.

Leilua retired late in the game with what appeared to be a bad cut to his leg.

Hooker Josh Hodgson could find himself in trouble for a possible grapple tackle in the first half.

MORE TO COME