The Dragons were trying to keep the magic alive for a second week running after toppling reigning premiers Brisbane last weekend.
But the Sharks unleashed a 15-minute scoring spree at Ocean Protect Stadium on Sunday, starting with a Briton Nikora angled run, followed by a William Kennedy swan-dive under the posts, then sideline speed from wingers Sam Stonestreet and Ronaldo Mulitalo.
It turned a 12-6 halftime deficit for the Sharks into a 16-point lead - and the Sharks weren't finished.
Cronulla coach Craig Fitzgibbon has had to reshuffle his line-up over the past fortnight with injuries to key players Nicho Hynes (calf), Blayke Brailey (arm) and Jesse Ramien (knee), as well as losing Origin players Addin Fonua-Blake and Nikora.
"Losing spine players is a really big challenge, and our week has been turbulent to be honest," Fitzgibbon said.
"To be fair to the players (coming in) they didn't slip at all and got the job done. We knuckled down on the simple things well and the simple things win games, so we're pleased with that."
He singled out former Dragons players Cam McInnes, Jesse Colquhoun and Billy Burns for outstanding performances.
Another converted try in the final 10 minutes on Sunday meant 28 unanswered points in the second half would ensure Cronulla rose from eighth to sixth in the standings.
The Dragons gave it a good shot. Scores were 12-12 early in the second half, and the lead changed four times during the match.
But lightning could not strike twice for Dean Young's Dragons, despite a strong first-half showing.
"It was pretty disappointing. Everyone probably got to see what the new Dragons look like and got a good look at what the old Dragons looked like," Young said.
The Dragons were camped inside the Sharks' 20-metre zone for most of the opening 40, so deserved their tries to centre Valentine Holmes and winger Matthew Feagai.
By contrast, the Sharks looked a little lacklustre trying to chase three wins on the trot, coughing up nine first-half errors.
But they flipped that script in the second half, led by five-eighth Braydon Trindall and an effervescent Kennedy, who re-signed with the club last week for a ninth season.
Trindall scored a try, landed five goals and kicked 16 times for 524 metres.
Kennedy topped the running metres count with 240 off 20 runs, alongside two line breaks, a try assist, and five tackle-busts.
"Will just gets better every year," Fitzgibbon said. "Thankfully we've managed to keep Will because he's the sort of guy that epitomises our team and club. He wants to be here and we love him."
This local derby usually brings out the best in these neighbouring clubs.
They play for the Monty Porter Cup in honour of the man who won premierships with the Dragons in the 1950s and 1960s and  was the Sharks' foundation captain in 1967.
The Dragons had the trophy in their cabinet after a 22-14 win last year, but now it returns to the Shire.
Cronulla will want to keep the momentum flowing when they face the second-placed Warriors in Auckland next Saturday, while the Dragons get to lick their wounds with a bye.
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