In the absence of rested regular half Nicho Hynes, the Sharks No.7 scored a try and set up two others at Suncorp Stadium as the visitors rebounded from a 12-4 halftime deficit.
The win ended a two-match losing streak for the Sharks and returned them to the top of the ladder.
Victory at Suncorp Stadium took Cronulla back to the top of the ladder. (Jono Searle/AAP PHOTOS)
The NRL issued Trindall with a breach notice last month after he pleaded guilty in court to mid-range drink driving and the presence of a prescribed illicit drug after an incident on April 22.
He was stood down by the Sharks to focus on his mental health and missed five games.
Saturday's clash with the Broncos was his second match back and the 24-year-old stood tall to play a key role in a stunning win in front of 41,004 fans.
The Sharks scored three tries in a devastating seven-minute spell after the break.
Cronulla's back five are a key strength and it was winger Sione Katoa who stepped his way through from a scrum with power and deception to narrow the margin to two points straight after the break.
Five minutes later, Trindall threw a dummy and blitzed his way past back-rower Brendan Piakura and the Sharks had the lead.
The Broncos had barely drawn breath after that double blow when a Trindall bomb was dropped by fullback Tristan Sailor and Blayke Brailey scored.
Sharks prop Royce Hunt came off the bench and was enormous with his energy and brute strength, while centre Jesse Ramien put in a stellar display to stake his claim to replace the suspended Joseph-Aukuso Suaalii in the NSW State of Origin side.
Brisbane captain Patrick Carrigan, backing up from Origin with Queensland, backed up a burst by hooker Billy Walters to score the opening try under the sticks after 11 minutes.
But the Sharks returned serve when back-rower Siosifa Talakai started and finished a left-edge attacking movement with brute strength.
The Broncos defended set after set on their own line as the Sharks launched repeated waves of attack but came up empty.
As so often happens, the Broncos then took their first opportunity up the other end.
Hooker Tyson Smoothy scored when half Jock Madden's grubber kick ricocheted back into Madden's arms.
The Broncos, with several players backing up from Origin, ran out of gas in the second half and made multiple errors, with their last-play options poor.
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