Adelaide claimed their first win since the opening round of the season and lifted the heat on Josep Gombau thanks to a crushing win against the defending champions
Without a win since their opening round victory over Perth Glory and with pressure quickly mounting on coach Josep Gombau, who lashed out at local media earlier this week - for the second time this season - the Reds were ultra-impressive in accounting for the reigning champions.
Embattled Gombau's side was expertly steered by fellow Spaniard Sergio Cirio, who set up Bruce Djite in the 25th minute and Fabio Ferreira in the 40th to give the Reds an overwhelming edge, before goaling himself early in the second half.
Jeronimo Neumann then iced it in the dying moments as United emerged triumphant over bogey side Central Coast for the first time since 2009.
Both sides had plenty of chances early, the Mariners butchering some early dollies to allow Adelaide breathing space and room to really pounce.
Steven Lustica found some space and let rip, high and wide, on four minutes, but it was the visitors who had two prime bites at the cherry three minutes later, which both went begging.
From a Central Coast corner, Trent Sainsbury miscued an open sitter, which landed at the feet of spearhead Daniel McBreen, who then shanked an absolute close-range gift.
Adelaide responded with a couple of near-misses, Carrusca's nice ball narrowly missed by a diving Djite on nine minutes, before Ferreira unveiled his bag of tricks and missed on his left by a slender margins with an exciting turning and spinning solo effort.
The Reds were playing an exciting brand and looked threatening.
Ferriera, fed by Carrusca, found the side netting from an acute angle in the 18th minute, with just Mariners custodian Liam Reddy to beat, before Djite gave the charging home side a deserved lead in the 25th minute when he pounced on a wonderful run and cross from Cirio and pushed it past Reddy.
After Djite's goal, all Adelaide players made a beeline for the Reds bench and warmly embraced Gombau, who has been under considerable heat in recent weeks.
McBreen copped a yellow card for dissent after former United star Marcos Flores was similarly booked, the Mariners under the pump and rattled.
Adelaide compounded the visitors' misery by doubling the margin in the 40th minute as red-hot Cirio set up Ferreira who closed in and tunnelled one between Reddy's legs.
The Mariners should have got one back in stoppage time shortly before the half-time whistle but were yet again left to kick themselves as McBreen slewed a weak lefty that rolled wide with just Adelaide goalkeeper Eugene Galekovic to beat, the Reds defence momentarily caught napping as the veteran marksman foiled the offside trap.
Ferriera was substituted off at half-time with a groin injury but it didn't deter the hosts, who continued to press and made it 3-0 in the 54th minute when Cirio slotted one of the more absurd, bizarre goals of the season.
The Spanish right winger was hot on the heels of Reddy with the ball seemingly on the path to roll gently past the goal-line.
The ball appeared just out when Reddy stopped in his tracks but with no whistle forthcoming, Cirio pounced.
He stole the ball, swivelled around and sprinted in the other direction to push it into the back of a completely vacant goal, Reddy caught napping and duly yellow carded for remonstrating with referee Ben Williams.
Michael McGlinchey and McBreen did their best to scare the notoriously leaky Reds with some late forays but for United's defence, playing with renewed purpose and steel, was up to the task.
Adelaide stung the off-colour Mariners with one final dagger on 90 minutes when Jeronimo, who replaced Ferreira at half-time, ran in on the counterattack and rifled it with precision past Reddy to cap a stunning demolition of the reigning champions.