The Sharks played the final hour without their halfback and had to survive a second-half surge from the Bulldogs, but did enough to improve to seventh spot on the NRL ladder.

However, with six games left to lock in a September spot, they face the prospect of being without one of their most important players for a large chunk of their finals push.

The Warriors-bound playmaker has battled hamstring issues for the past two years.

"One thing I know about Shaun is he looks after himself," caretaker coach Josh Hannay said.

"He's a reasonably quick healer. I know he'll jump into his recovery, rehab and do everything he can to get back as quick as he can. We won't be jumping at shadows. We'll assess it, see where it's at.

"And we'll get him back when he's ready."

Cronulla looked set for a cruisy Sunday afternoon when they blew the contest apart with three tries in the space of six minutes to set up a three-try halftime advantage.

A more enterprising Canterbury threw caution to the wind in the second period to twice get within 12 points before slumping to their fifth straight defeat and 10th in their past 11 games.

Bulldogs prop Luke Thompson was the best player at Cbus Super Stadium, making up for his first-half sin-binning by finishing with arguably his most impressive performance since moving to Australia.

The Englishman nabbed a first-half try, set up another, and racked up a team-high 190 metres and nine tackle busts to go with two line breaks and 27 tackles.

However, he alone couldn't compete with a Cronulla pack that had all five starting forwards crack the 100-metre mark, including a game-high 208 metres from bullocking second-rower Siosifa Talakai.

Front-rower Toby Rudolph was also immense with 154 metres and five tackle busts.

Winger Sione Katoa bagged two tries, while five-eighth Braydon Trindall, filling in for the injured Matt Moylan, put on a kicking clinic by nailing eight of his nine attempts.

Canterbury appeared to weather an early two-try ambush from Cronulla, one of which included an acrobatic Katoa finish, when Thompson crashed over from close range in the 22nd minute.

But two mindless acts turned the momentum.

Dylan Napa turned the ball over with an attempted offload from the restart, before Thompson spoiled his earlier effort with a late shot on Jayden Brailey, leaving him on report.

"Our first half was really poor," Bulldogs coach Trent Barrett said.

"Kick out on the full, play one, offload after kick-off, those sort of things you can control, and you can't do them."

It was a procession for the rest of the half, the Bulldogs defence surrendering as the Sharks ran in three quick tries, the second of which ended in Johnson limping off after putting Briton Nikora away.

Just as it looked as though the Sharks were going to run away with the contest, the Bulldogs opened the second half with two tries in the space of three minutes.

Australian Associated Press