Without a coach, captain Paul Gallen or the sacked Todd Carney, the Sharks were expected to be pulverised as cannon fodder at Allianz Stadium.

Instead they came back from 24-0 down to hit the front through a Jeff Robson try with three minutes remaining and then survived a controversial call when referee Gavin Morris ruled 'no try' on a possible Mitch Aubusson touchdown with 11 seconds left because he was unsighted.

Video referees Steve Chiddy and Steve Folkes were unable to find enough evidence to reverse the on-field decision to deny what would have been Aubusson's third try.

It was one of the most unlikely results in recent NRL history. An 18-point halftime margin became 12 when 21-year-old winger Jacob Gagan scored from Fa'amanu Brown's kick three minutes into the second half.

Then it took a magnifient effort from Dylan Napa to prevent replacement Tim Robinson scoring by holding him up in-goal. The pain was merely delayed for Trent Robinson's side, with winger Sosaia Feki crossing not long afterwards.

The six-point margin stayed for five tense minutes. Aubusson gave the Roosters some breathing space when he crossed for his second try at 57 minutes.

But the Sharkies kept gnashing their teeth, Gagan crossing for his second with seven minutes remaining and Michael Gordon converting from the sideline.

The Roosters' first try came as a result of some dazzling left-side handling, with Shaun Kenny-Dowall, Nene McDonald and James Maloney combining for Aubusson to cross unopposed.

That was in the fifth minute. The next Roosters try came in the ninth. Sam Moa and Jake Friend provided the lead-up in mid-field and halfback Mitchell Pearce reaped the rewards with his fourth touchdown of the year.

Winger McDonald charged through the teeth of the Cronulla defence at the 15-minute mark and found centre Shaun Kenny-Dowall in support; the third Tricolours try was followed by five-eighth Maloney's third consecutive conversion.

There were those already muttering about a mercy rule.

But Cronulla were unfortunate that Gagan had a try chalked off after 21 minutes. Video referees Steve Chiddy and Steve Folkes found Brown had run behind Tupou Sopoaga in the lead-up, obstructing the defence.

But the besieged Sharks continue to give cheek, Sam Tagataese making. Long break, before quick hands put Sydney Roosters debutant Brendan Elliot over in the south-western corner.

Pearce then experienced a double blow when his own would-be try from a bomb was chalked off and he threw the ball straight to rival captain Wade Graham for he visitors' first try.