After falling behind 14-0 early in the first half, the Sharks were able to set up a grandstand finish in Coffs Harbour before falling short on Friday night.
First on the ladder six weeks ago, Cronulla are now dangerously close to following in the footsteps of South Sydney from last season.
In a worst-case scenario Craig Fitzgibbon's men will finish the weekend in fourth spot, but could be as few as three points clear of ninth place.
The Sharks still have a friendly run home compared with other top-eight hopefuls, but now desperately need to turn their form around.
Gold Coast were well on top from the outset on Friday night, having the first 20 play-the-balls in attack before eventually capitalising.
Kieran Foran stepped through for the Titans' first, before putting Chris Randall through a gap in the middle for Gold Coast's second.
In contrast, the Sharks couldn't take their chances.
Royce Hunt missed one opportunity when he dropped the ball just short of the tryline, and Jack Williams fumbled another ball on attack.
Another chance went begging when a flat Nicho Hynes pass was called forward, as Jesse Ramien crashed over the line.
Under intense scrutiny in recent weeks, Hynes had an improved night on the NSW north coast.
The Titans made a clear point to target the Sharks half, forcing him to make 18 tackles in defence as he held his own.
Hynes also helped create the space in the lead-up to Cronulla's first two tries in the second half as they launched a comeback, before finishing off their third.
Down 14-0, the halfback spread the ball right to allow Briton Nikora to offload for Braydon Trindall for Cronulla's first.
After the Titans hit back to make it 20-4, Hynes went right again before Trindall put on a lofted ball for Dan Atkinson.
And after blowing a chance to streak away when he spilled a ball in broken play, Hynes scored Cronulla's next after Ronaldo Mulitalo and Will Kennedy combined on the previous tackle.
That gave the Sharks four minutes to try to steal the game, but ultimately the Titans were able to hold on and claim their fifth win of the season.
David Fifita was solid for Gold Coast in his bid to win back a Queensland State of Origin jersey, as Billy Slater weighs up his side for the July 17 decider.
Cronulla second-rower Siosifa Talakai could also face scrutiny from the NRL's match review committee after being sin-binned for a shoulder charge in the first half.
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