The injury-hit Cronulla Sharks consigned Melbourne Storm to a shock 20-18 NRL defeat on Friday after the fit-again Jason Taumalolo had inspired North Queensland Cowboys to victory over Gold Coast Titans.

Cronulla were without crocked key men Shaun Johnson, Matt Moylan, Wade Graham and Aaron Woods, but pulled off a big triumph in the face of such adversity.

Kyle Flanagan, a 20-year-old half-back, was among the young Sharks to rise to the occasion in only his third NRL game, relishing the responsibility as playmaker in his first start.

Both sides scored two tries in a first half that ended 12-12, Sione Katoa and Briton Nikora scoring for the Sharks either side of Josh Addo-Carr and Jesse Bromwich going over at the other end.

Flanagan set up Nikora's four-pointer with a grubber kick and slotted over a penalty 10 minutes into the second half before Braden Hamlin-Uele barged his away over for a first NRL try.

Ryan Papenhuyzen's try gave Melbourne hope, but they were unable to avoid a second defeat of the season as the Sharks moved just outside the top eight.

Taumalolo, meanwhile, made up for lost time on his return from a knee injury in the Cowboys' 28-14 defeat of the Titans.

The New Zealand international - sidelined since the game against the Brisbane Broncos on March 22 - scored the Cowboys' second try, with Jake Granville, John Asiata and Justin O'Neill also touching down in a third win of the season for the Cowboys.