A 19th-minute sucker-punch goal from Ali Auglah was enough for the Mariners to shake up the championship race with a watershed 1-0 win in Auckland on Sunday.
The rueful defeat leaves the second-placed New Zealand outfit unable to bridge a four-point gap to the Jets in next weekend's final round of matches.
Auckland's top-two spot is also suddenly vulnerable. Sydney FC could snatch second position with a three-goal win over the Black Knights at Allianz Stadium next Sunday.
The Jets, though, will be overjoyed and lap up being presented the Premier's Plate after next Saturday's F3 derby against their arch rivals the Mariners in Newcastle.
Having also claimed the Australia Cup, the Jets can also become the first team in history to complete a glorious treble if they take out the championship.
Sunday's high-stakes encounter erupted in the 13th minute when Central Coast defender James Donachie was yellow-carded for unnecessarily treading on Auckland striker Sam Cosgrove after the pair collided in a mid-air challenge.
Officials deliberated over replays for several minutes before opting against issuing a red card, saying they could not be certain Donachie's reckless act was intentional.
"It's obvious," Cosgrove told Paramount Plus.
"It's either accidental and it's not a foul, or it's intentional and it's a red card. There's no in between.
"And that can change the game. And it's a poor decision for their goal. We (should have) had a corner.
"But, listen, we didn't do enough to win the game after that. There's no point dwelling."
For now, the Jets have the ninth-placed and out-of-contention Mariners to thank for fashioning one of the upsets of the season, a first-ever win over Auckland no less.
Adding to Auckland's anguish, the Mariners defied an alarming lack of possession to mount a sweeping counter-attack that ended with Auglah putting away a sumptuous through-ball from Nathanael Blair and taking a shock lead.
Teenage midfielder Jessie Mantell skilfully initiated the attack, winning possession then setting Blair free down the left.
Days after committing to Iraq, Auglah's third goal in four games further enhanced his claims for a call-up from Graham Arnold for the looming World Cup.
Suddenly, Auckland needed to win from 1-0 down for the first time all season to keep alive their hopes of snatching the Premier's Plate from the Jets.
And they couldn't.
Former Socceroos goalkeeper Andrew Redmayne was arguably the Mariners' best, but the skipper still branded the side's first win in five meetings with Auckland bittersweet.
"There's a lot of character in this team and we were kind of saddened by the prospect that we're not playing finals," Redmayne said.
"But we wanted to come out here and set the set the record straight, I guess."
Auckland's frustrations boiled over when Lachie Brook was booked for dissent, the midfielder furious about not earning a throw-in deep in attack.
It was the second week in a row Brook had been yellow-carded for an over-reaction and he's walking a tightrope ahead of the finals.
If there wasn't enough thunder and lightning on the pitch already, players were forced off the field 10 minutes before halftime as a storm lashed Go Media Stadium.
Auckland emerged from the 30-minute stoppage energised and refocused - but they could not find an equaliser.
Redmayne was called on to save numerous shots on target but it was Donachie's miraculous goal-line intervention of a 68th-minute Brook header that best symbolised the Mariners' spirited defence.
