Cronulla have fought back to ambush the Warriors and spoil Roger Tuivasa-Sheck's homecoming with a gutsy 16-12 win in Auckland.
To make matters worse for a clumsy Warriors outfit, hooker Wayde Egan left the field with an apparent elbow injury in his first game since enjoying a career-best 2023 season.
The Sharks' away win over last year's preliminary finalists comes as they look this season to once-and-for-all shake their reputation as a good side unable to match it with great sides.
"There's a long way to go in the season and we can be better but the display of heart and effort was awesome," Sharks coach Craig Fitzgibbon said.
"That was one of our most special wins, I think."
Early on Friday night, the Warriors showed flashes of what made them the NRL's surprise success story in 2023, with Shaun Johnson's kicking game at its pinpoint best.
Led by Shark-in-waiting Addin Fonua-Blake, the Warriors stormed to a 12-0 lead after 13 minutes and it looked as though Cronulla would once again fold in the face of a highly-rated foe.
Cronulla's middle forward unit, weaker on paper than those of other premiership heavyweights, was seriously brittle as Fonua-Blake crashed over and Luke Metcalf cut through four defenders early.
It took 30 minutes for the Sharks to enter the Warriors' 20-metre zone.
But Cronulla were patient and began to pounce when errors crept into the Warriors' game later in the first half.
"Our defence, our ruck control, just weren't good enough," said Warriors coach Andrew Webster.
"We were clunky, didn't have the right timing."
The Sharks wisely chose to attack wide once in position and were right in the game after Jesse Ramien and Ronaldo Mulitalo stormed over on opposite edges either side of half-time.
Both four-pointers came directly after Warriors mishaps.
Ramien was in position thanks to a dangerous tackle from Bunty Afoa before Tuivasa-Sheck spilt the ball to march the Sharks upfield for Mulitalo to score.
It was down Mulitalo's left edge that the Sharks took their first lead of the night through Siosifa Talakai midway through the half.
Fonua-Blake gave the Sharks an early taste of what he will bring to the Sutherland Shire from 2025 with 180 metres.
He almost had a second try bursting through Blayke Brailey and into the red zone during the second half.
Tohu Harris was monumental for the Warriors through the middle as well with 232 metres to the good.
Favourite son Tuivasa-Sheck made a modest return to the Warriors after a two-year hiatus playing rugby union.
He looked comfortable running the ball but twice turned it over and was pulled up short by Cronulla's solid goal-line defence as he looked a chance to level the scores in the last five minutes.
Nicho Hynes made a try-saving tackle around Jackson Ford's legs in the final 90 seconds that sealed the result.
"It was almost like we had to blow the cobwebs out or something," Fitzgibbon said of his side's slow start.
"Then we just kept turning up."
Egan left the field after being crunched awkwardly as the Warriors banded together to push Talakai into the in-goal midway through the second half.
Freddy Lussick replaced him and is the obvious choice to start at hooker should Egan miss time.
