Off the back of two straight losses and after trailing at halftime, Cronulla went from 18-6 down to 22-18 up between the 47th and 57th minutes on Thursday night.
The hosts then did enough to hold on for victory at Shark Park, making it 10 in a row against their arch-rivals and keeping the Sharks fifth on the ladder.
Trindall's kicking was at the centre of it all, while the Cronulla five-eighth also scored a double in the victory.
Blayke Brailey was among the Sharks' best with his running out of dummy-half, while Sione Katoa bagged a double in the win.
The winger's last try to seal the match will also go down as one of the best of the year.
With the Dragons down 24-18 with five minutes to play, five-eighth Lyhkan King-Togia chipped ahead and went to toe the ball on again.
But Katoa slid along the ground to catch the ball goalkeeper-style, before gathering his feet and sprinting 60 metres to score.
The result makes it two losses in a row for the Dragons, with Shane Flanagan's men now 12th and at risk of sliding further south this weekend.
For the Sharks, this was a desperately needed win.
Beaten by an undermanned Sydney Roosters in Gosford and travelling Warriors in their past two matches, Cronulla travel to Brisbane and Melbourne in the next fortnight.
"It's too big of a picture to look at it like that," Sharks coach Craig Fitzgibbon said.
"We're where we're at, we haven't performed for a couple of weeks. Even the result today was irrelevant.
"It was the performance that was needed.
"We needed to see what we want to be and do. We just needed to play like the Sharks, that was the most important thing out of tonight."
Cronulla looked at their best with Brailey running out of dummy-half, and the hooker laid on the Sharks' first when he sent Trindall over early.
But after that, the Sharks defence began to break.
Dragons veteran Damien Cook turned back the clock for one try and King-Togia beat four defenders for another.
And when Jack de Belin went over with Sharks centre Jesse Ramien in the sin-bin for a professional foul it was 18-6.
Then after the break Cronulla's forwards started to get a roll on, the wind picked up and Trindall chose his moments to terrorise the Dragons.
The five-eighth first put Briton Nikora over with a short ball, before staying alive to score from one of his own bombs after Clint Gutherson and Tyrell Sloan failed to defuse it.
The go-ahead try then came when Nathan Lawson dropped Trindall's next bomb, and Katoa skipped to the outside of Dragons centre Moses Suli from the scrum to score.
"They ran a little harder in the second half, got good field position and all their kicks were contestable," Flanagan said.
"You have to make them kick long, and they were all contestable kicks. And we didn't handle the kicks.
"There's 12 points, there's the game off two kicks."
The only concern for Cronulla came in the form of a knee injury for Mawene Hiroti, just a week after fellow centre KL Iro was ruled out for two months with a pectoral tear.
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