With all eyes on Nicho Hynes, it was his halves partner Trindall who delivered for the Sharks as they set up a preliminary final against three-time defending-premiers Penrith next Saturday night.
After Cronulla took a 24-0 lead into the break in Friday night's semi-final, North Queensland threatened a second-half comeback when they got it back to 24-12 with 25 minutes left.
But ultimately an uncontestable Scott Drinkwater dropout that went out on the full sealed the Cowboys' fate, allowing to the Sharks to kick 26-12 clear.
North Queensland again hit back to 26-18 with 10 minutes to play but the Sharks were able to hold on and place themselves 80 minutes from a grand final.
Ronaldo Mulitalo got among the scorers as the Sharks built a 24-0 lead by halftime. (Dan Himbrechts/AAP PHOTOS)
The win ended Cronulla's seven-match losing run in finals, and marked their first post-season victory since the semi-finals of 2018.
Friday night had loomed as the Sharks' most important game since the 2016 grand final, given their struggles in finals matches and question marks over Hynes's form.
But they showed no signs of nerves in the first half, with Trindall overcoming his own personal issues this year to stand tall.
The five-eighth was superb, scoring a double and having a hand in two other tries as he took on more control of Cronulla's attack.
His first of the night was the most controversial, getting the Sharks' opener via a penalty try when he was taken out by Reuben Cotter while chasing through on his own grubber kick.
Another try came when Trindall put up a bomb, stayed alive on the play and scored after Briton Nikora batted the kick back and Jesse Ramien flicked the ball out to the No.6.
Nicho Hynes responded to criticism with a strong game that included five goals from five attempts. (Dan Himbrechts/AAP PHOTOS)
North Queensland's inability to diffuse kicks was an issue throughout the first half, with another Sharks try coming when Ronaldo Mulitalo out-leapt Kyle Feldt on a Hynes bomb.
On that occasion it was Trindall who picked up the loose ball, before flicking it back for Cameron McInnes to reach over the line and score.
And when Trindall helped Kayal Iro send Mulitalo over just before halftime, the Sharks' 24-0 lead appeared unassailable.
While Cronulla were denied twice by the bunker in the second half, it was Trindall who forced the dropout late that allowed the Sharks to take a 26-12 lead.
As good as Cronulla were, this was North Queensland's season summed up in a nutshell.
Inconsistent from week to week and within games in 2024, the Cowboys turned up 40 minutes too late to their most important game of the year.
Valentine Holmes scored twice in the second half and Cotter crossed after a batted-back kick.
And while Reece Robson threatened out of dummy-half with a mid-field break at 26-18 down late on, it was all too late for the Cowboys.
Adding to the pain, departing North Queensland veteran Feldt limped off early with calf damage, while Holmes suffered a leg injury.
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