A frustrated Trent Robinson is questioning why Melbourne were awarded a controversial try in the Sydney Roosters' 18-12 loss to the Storm.

Back-rower Eli Katoa barged his way over the Roosters' line midway through the first half at Sydney Football Stadium on Thursday night.

But as he fended off Michael Jennings and Luke Keary to ground the ball, replays appeared to show Jennings had been driven off the tackle by Storm prop Nelson Asofa-Solomona.

Taking opposition players out of a tackle is illegal.

But despite replays and several reviews from the bunker, the try was awarded and proved decisive in a six-point win.

Robinson was visibly angry when cameras panned to him in the box and that theme continued in his post-match press conference.

"It's really clear, they (the NRL) came out at the end of the year and if you lend weight to a tackler in a stationary or forward momentum, then it'll be stopped," Robinson said.

"Or if it's in a try it's going to be a penalty.

"It's really quite simple, he (Asofa-Solomona) runs in from distance, touches his player and Jenko (Jennings) and his player scores.

"Did he lend weight to the play? Yes he did."

Robinson was also left annoyed by the failure of referee Ashley Klein during the build-up to Xavier Coates' match-winning try.

Melbourne centre Reimis Smith appeared to disrupt the Roosters' hopes of fielding the ball.

It was telling in a game — arguably the worst of the season thus far, marred by 22 errors and 17 penalties — that all five tries came from final-tackle play kicks.

Melbourne drew first blood 13 minutes into the game when Jahrome Hughes sent up a kick that winger Will Warbrick was able to bat back into the arms of Katoa.

The Storm back-rower found Hughes racing onto the ball, the halfback evading James Tedesco and Daniel Tupou to score the opening try of the night.

Jennings hit back for the Roosters by diving on a loose ball in the in-goal before Katoa restored Melbourne's six-point lead with his controversial try.

Leading 12-6 at halftime, Melbourne kept hammering but couldn't find a way through and their hunt to open up a gap was compounded by Cameron Munster being sent to the sin bin for a professional foul.

Munster returned but eventually the Storm's resolute defence cracked as rugby union-bound Joey Manu crossed with 10 minutes left.

Coates, however, was able to continue his trend of scoring at the death, barging his way over to give the visitors the victory.

Craig Bellamy's side have now beaten the Roosters in nine of their last 10 attempts and move up to first.

"It looked like we were taking the easy options a little bit too much, we just had to have a little bit more patience," Bellamy said.