IT was advertised as 'Survival Sunday' and, from a Sunderland perspective, it more than lived up to its billing.
Out of the bottom three for the first time since the start of February courtesy of the club's biggest victory since September 2011, this felt like the afternoon when relegation was avoided.
It wasn't of course, and with three games remaining and only goal difference separating them from 18th-placed Norwich City, the Black Cats cannot afford to assume that the hard work is done. Sunderland still have to travel to Old Trafford before entertaining West Brom and Swansea in the final week of the season, and they might yet have to claim four or five points to be absolutely certain of safety.
But after weeks of slipping inexorably towards the abyss, Gustavo Poyet's players have finally changed the narrative of a season that has already contained more than its fair share of highs and lows.
Momentum is a crucial asset in a relegation battle, and while the four-point haul gained from away games at Manchester City and Chelsea altered the mindset of a club that had all but given up the ghost in the wake of this month's thumping 5-1 defeat at Tottenham, there was still a massive question mark over Sunderland's ability to beat the sides in and around them in the table.
Not any more. The controversial first-half dismissal of Cardiff defender Juan Cala might have eased their task considerably, but there was still much to admire in the convincing and clinical manner in which the Black Cats set about dismantling a side who came with the initial intention of strangling their attacking ambitions.
Connor Wickham had already broken the deadlock when Cala was sent off for hauling him back, and when the reborn striker completed the rout with five minutes remaining, Sunderland had produced by far their most accomplished display of the season.
Winning against the odds at the likes of Chelsea is one thing, but it is the ability to win the games you are expected to that generally decides your Premier League fate. The Black Cats have been unable to beat teams in the bottom half of the table all season, but when the stakes were at their highest, they finally delivered the kind of vibrant attacking display that had eluded them time and time again earlier in the campaign.
Why the sudden improvement? Well, Wickham's presence is undoubtedly a key factor, with the striker now having scored five goals in his last three appearances since being recalled from a loan spell at Leeds United.
For the last three years, Sunderland have searched desperately for a player to put the ball in the back of the net. It turns out they had him in their ranks all along.
Wickham's success in front of goal has transformed his side's fortunes, with yesterday's two headed strikes showcasing a physical strength and desire to out-muscle his opponent that was impossible to discern in the other centre-forwards who have featured this season.
An ability to apply the final touch is only part of the story though, with the quality of Wickham's approach work and hold-up play also playing a pivotal role in Sunderland's sudden development of a potent attacking threat.
GOOD FORM: Connor Wickham celebrates his first goal of two
Behind the 21-year-old, things are also starting to function more effectively, with Jack Colback and Seb Larsson combining to provide creativity to go along with the combativeness that is Lee Cattermole's trademark.
All three were excellent yesterday, with Colback in particular taking full advantage of Cardiff's numerical limitations in the second half. Poyet's refusal to bring Liam Bridcutt straight back into the team at the expense of Cattermole should also be applauded.
Similarly, the Uruguayan's decision to stick with Santiago Vergini ahead of Phil Bardsley also paid off, with the Argentinian full-back providing some welcome defensive solidity on an afternoon when Cardiff's attacking threat petered out at an early stage.
In truth, the visitors never really got going at all, and whereas a number of previous home games had seen extremely slow starts from the players in red-and-white, yesterday's match featured an intensity and tempo from the word go.
Sunderland forced two corners inside the opening four minutes as they found themselves camped in the Cardiff half, and while Larsson could only direct an eighth-minute header straight at David Marshall, the momentum was firmly with the hosts from the outset.
The opener finally arrived midway through the first half and, from a Sunderland perspective, it could hardly have been simpler. Larsson's corner travelled across the length of the six-yard box, and Wickham held off Kevin Theophile-Catherine to plant a downward header back across goal and into the far corner of the net.
Having conceded a succession of goals from set-pieces this season – 17 at the last time of counting – it must have felt especially sweet for Sunderland to profit from some wretched defending.
HIGH KICK: Marcos Alonso rises high to clear a chance
Worse was to follow from a Cardiff perspective, much worse in fact, with Cala seeing red on the stroke of half-time as he attempted to atone for a dreadful attempt at a back-pass that afforded Wickham a clear run on goal.
Cala's tug on his opponent began outside the area, but it continued into the box and FIFA's rules clearly state that such an offence should result in a penalty. As he had at Chelsea, Fabio Borini converted from the spot with aplomb.
That Cala was the last defender, and therefore culpable of a professional foul that had to result in a straight red card, was never in doubt, and referee Phil Dowd duly obliged.
To Wickham's credit, he attempted to stay on his feet after he was fouled, and Dowd deserves huge merit for attempting to allow play to continue, only to come back to the initial foul three or four seconds later when Sunderland failed to create a chance.
If we are to call on players not to automatically go to ground when they are fouled, then the officials have to be allowed to bring play back if they are unable to gain any advantage.
Reduced to ten men, it was always going to be a tough task for Cardiff to get back into the game, although things might have been different had Vito Mannone not flung himself to his right to keep out Peter Whittingham's deflected free-kick.
Twelve minutes later, and Sunderland were celebrating a third goal, with substitute Emanuele Giaccherini slotting home after Borini had released him behind the Bluebirds' back four.
The fourth success arrived with five minutes left, with Wickham again holding off Theophile-Catherine to head home Giaccherini's corner from the edge of the six-yard box.