The Cowboys just need to beat the struggling Wests Tigers on Saturday night to guarantee a top eight finish, a remarkable proposition considering their dire straits just over a month ago, when Neil Henry was sacked from the final year of his contract.
It was another unwanted Cowboy who stole the show for the visitors, with Matt Bowen - who on Friday announced he had no future at the club beyond this year - turning back the clock with a vintage display.
The veteran fullback scored the opening try and then set up three of his side's four tries - but it wasn't until Johnathan Thurston nailed a field goal with just over a minute remaining that the win was in the bag.
Gavin Cooper's second try of the afternoon - his seventh in six games against the Sharks - merely iced the game for the visitors, who will take incredible momentum into their last round encounter and shape as a finals danger team.
The Sharks, without pivot Todd Carney due to a hamstring injury suffered in Saturday's final training run - with scans to determine the length of his layoff - struggled to pose the Cowboys too many problems.
It could get worse for Cronulla with skipper Paul Gallen put on report for a crusher tackle on Scott Bolton midway through the second half.
It was nip and tuck throughout the contest, with no side leading by more than a converted try before Thurston's late one-pointer.
The Cowboys lost Test prop Matt Scott inside the first ten minutes with a broken finger, which coincided with Jeff Robson giving the home side the lead with an individual try.
Bowen then turned it on with an individual try of his own, two short balls in the space of four minutes after the break for Cooper and then Tariq Sims turning an 18-12 deficit into a 22-18 lead just before the hour mark.
NORTH QUEENSLAND 31 (G Cooper 2 M Bowen T Sims B Tate tries J Thurston 5 goals J Thurston field goal) bt CRONULLA 18 (J Bukuya 2 J Robson tries M Gordon 3 goals).
Referees: Shayne Hayne, Luke Phillips.
Crowd: 15,313 at Remondis Stadium.