Manly has kept its finals hopes alive and undermined Cronulla's campaign with a brave and nail-biting 30-26 win over the Sharks.

In Sunday's earlier match, Penrith stayed on top of the ladder with a 44-18 victory over Canterbury.

At Shark Park, the Sea Eagles overcame the loss of prop Taniela Paseka in the opening five minutes with a knee injury, then withstood a fierce late fightback from Cronulla to deny the home side in a thriller.

Looking dead and buried when they trailed 30-0 early in the second half, the Sharks threatened to pull off a remarkable comeback.

The match looked all but over at half-time after Reuben Garrick crossed seconds before the break to give Manly a 24-0 lead.

And shellshocked Sharks fans began filing out when Manly centre Toluta'u Koula bagged his second try four minutes into the second half.

But Cronulla then replied with five unanswered tries to Ronaldo Mulitalo, Sione Katoa, Cameron McInnes, Jesse Ramien and Will Kennedy to set up the grandstand finish.

The Sharks then had the chance to snatch an unlikely victory, but Kennedy opted to go himself when the hosts looked to have Manly stretched for numbers on the left.

Aside from Koula's double and Garrick's try, the Sea Eagles also crossed the stripe through Josh Aloiai, Lachlan Croker and Haumole Olakau'atu.

While Manly climbed to within one point of the top eight, Cronulla remains sixth with a treacherous run to the finals after blowing a golden opportunity to rise to third through its ill-disciplined display.

The Sea Eagles have a far more favourable run home and could yet feature in the finals if they can fashion four wins from matches with St George Illawarra, Sydney Roosters, Penrith, the Warriors, Canterbury and the Wests Tigers.

Penrith celebrated Nathan Cleary's return from injury by comfortably defeating Canterbury.

The Panthers inflicted the bulk of the damage in the opening exchanges, running in 28 unanswered points in 30 minutes to put the match beyond doubt.

The only sour note for the Panthers was a suspected medial cruciate ligament injury to Spencer Leniu that forced the interchange prop from the field in the first half.

As was the case in last week's loss to Brisbane, the Bulldogs showed fight for periods of the match, scoring only four fewer points than the Panthers in the second half.

But the Bulldogs shot themselves in the foot when the contest was in the balance.

Halfback Cleary showed no signs of the hamstring injury that had kept him out since round 14 and was his busy self on return.

He ran the line that led to the first of Brian To'o's two tries and then swung left to give the Panthers the overlap that confirmed a double for Tyrone Peachey as well.

In the second half, a beautiful flat ball from Cleary sent Luke Garner over on the right for his first try as a Panther.

Goal-line defence has been a particular area of concern for the Bulldogs in recent weeks and six of Penrith's eight tries came from close range.

The Panthers proved capable of punishing from long range as well. To'o ran 70 metres from a kick return for the most exciting try of the afternoon.

Bulldogs coach Cameron Ciraldo hoped late changes to his spine formation could spark his side.

He benched co-captain Reed Mahoney, started Kyle Flanagan at hooker, promoted Hayze Perham to fullback and pushed Jake Averillo into the halves.

But by the time Mahoney came onto the field the Bulldogs were four tries down, although they did manage to stem the bleeding around that time.

They scored their first try of the afternoon late in the first half, enjoyed all the territory to begin the second term and kept Penrith to only one try in 29 minutes across the break.

But the result was never in doubt as the Panthers cruised to a big win with three second-half tries.

AAP/ABC