Melbourne Storm and Sydney Roosters overcame injuries to star players to record NRL wins over New Zealand Warriors and St George Illawarra Dragons.

The Storm ran in nine tries - three of which were scored by Suliasi Vunivalu - in a 50-6 thrashing of the Warriors.

However, they lost Cameron Munster to a knee ligament injury that is expected to keep him out for at least the next four weeks.

Meanwhile, the Roosters, who were already without James Tedesco and Josh Morris, had Victor Radley and Sam Verrills go off with suspected anterior cruciate ligament injuries in a battling 26-12 triumph over the Dragons.

Munster sustained his knee injury four minutes into the Storm's contest but continued until half-time before calling it a night, with Melbourne already 22-0 up.

As well as Vunivalu's treble, Paul Momirovski and Ryan Papenhuyzen both crossed twice while Brandon Smith and Josh Addo-Carr scored late tries to go along with Cameron Smith's 14 points from the boot.

Melbourne face the Roosters next, and they could meet a Sydney team depleted by injuries after Radley and Verrills both suffered possibly serious knee problems in the first half against the Dragons.

Sydney went 10-0 up through tries from Brett Morris and Jared Waerea-Hargreaves - the second coming after Tedesco's stand-in Joey Manu had collected his own kick and flicked a brilliant no-look pass to the try-scorer.

The Dragons fought back, though, courtesy of scores from Mikaele Ravalawa and Zac Lomax, who then slotted over a 46th-minute penalty to put them ahead.

Yet Brett Morris - the brother of Josh - completed a second-half hat-trick either side of a score from Luke Keary to move the Roosters up to second.