The Bulldogs' loss was compounded after Josh Morris suffered a worrying knee injury and did not return after halftime.

The Canterbury centre will be sent for scans on Monday after injuring his left knee in the 25th minute tackling Jesse Ramien.

He left Southern Cross Group Stadium in a moon boot and the off-contract veteran may have played his last game for the club.

After scoring his 100th try for the club with the opening four-pointer, the afternoon quickly went sour for Morris and the Dogs, who did not lead again after the 14th minute.

After a slow start and a difficult month marred by injuries, Shane Flanagan's men are 7-4 and warming into the season.

With skipper Paul Gallen (knee) and Josh Dugan (foot) making their returns from injury, the Sharks weren't always pretty but got the job done in front of a 14,004-strong crowd.

"It's pleasing especially on the back of who's been out the last six weeks, our whole back-row, our most experienced players, Gal, Luke Lewis, Duges and Wade Graham. That's a fair effort," Flanagan said.

"It gives me real confidence where we're at as a club and our younger players getting an opportunity.

"Blokes like Gal know these younger blokes are coming to get them. They've got to play good as well. It's how we like it."

Sharks prop Andrew Fifita continued his stellar form, running for 171 metres and making 33 tackles.

Front-row partner Matt Prior was the unlikely hero, scoring the match-winning try.

Their Bulldogs opposite David Klemmer sent a reminder to NSW Origin selectors with 233 metres off the bench.

After scores were level at 10-10 at halftime, Ramien sliced through four defenders to give the Sharks a six-point advantage.

The Bulldogs' got their third try in the left-hand corner when Brett Morris finished off a sharp movement made possible by some quick hands from Kerrod Holland to get back within two points.

But the Dogs shot themselves in the foot from there.

Between the 43rd to the 67th minute the visitors conceded a run of five penalties.

And the pressure eventually told when Prior crashed over the top of Jeremy Marshall-King for what proved the match-clinching try.

Kieran Foran had a chance to set up a grandstand finish but grounded the ball just short of the line.

Dean Pay's side were once again brave and gritty but he said he was tired of that narrative after their sixth loss in eight games.

"We're sick of sitting here saying it," Pay said.

"We're just shooting ourselves in the foot all the time. We started the game with five-nil (penalty count) and we started the second-half with a five-nil penalty count. It just takes the juice out of you. You've got to be smarter."

Australian Associated Press