The Football Association's vision of a Wembley showpiece on semi-final weekend is starting to look more like the Football League play-off finals.
Whatever Barnsley can do, so can Cardiff. The remaining participants may make far from pleasant reading for the Soho Square bean-counters, for whom image is everything, but what refreshing reading this year's last four makes, a sole Premier League representative, Portsmouth, providing a welcome antidote to the grinding monotony of a competition monopolised by the "Big Four". "It's the year of the underdog," Dave Jones, the Cardiff manager, said.
Two goals up in the opening quarter, a side stuck in Championship mid-table made light work of a third away draw in four to seal their place in the semi-finals for the first time in 81 years. Then, they were the first and only club to take the Cup west of Offa's Dyke.
"I have 1927 rammed down my throat every day," Jones said after his side took a huge stride towards updating that nagging statistic. "It's a long road and we're building towards a bright future and you've got to dream."
As they contemplate the magnitude of their achievement – and there was nothing fortunate about this victory – the irony will not be lost on them that for the next stage they must travel to the capital, barely a year since their own city's Millennium Stadium was hosting games of similar magnitude.
As for a desperately poor Middlesbrough side, they were left with only a lingering, nagging sense of regret over what might have been. But it would be grossly unfair on Cardiff to put this defeat down to the ineptitude of Gareth Southgate's men, as much as they were guilty of a shockingly ordinary performance.
There is clearly something about the Welsh that unsettles them, Wrexham being the last lower-division club to knock them out of this competition, eight years ago. "Whether we froze or whether the occasion was too much, I don't know," a bemused Southgate said.
Victory – which brings a welcome injection of funds to a club with well-publicised financial troubles, including a court appearance due later this week over debts of £24m – was ample revenge for Jones, who, as manager of Stockport County 11 years ago, was denied a trip to Wembley in the League Cup by the Teesside club.
"I don't know what it means for our financial future," Jones said. "I leave it to the people who know what they're doing to sort the court case out."
A Welsh club representing the FA in Europe as winners of an English cup remains an intriguing possibility. "It would certainly cause a stir," Jones said, before aiming a sly dig at the negative attitude he regularly faces from locals. "If we went and won it, they'd only tell us we won't do well in Europe."
Not even the prospect of a turbulent flight back to Wales held any fears for the victors. Jones said: "The plane will be rocking anyway. Someone asked for champagne in the dressing room. I said, 'For what?' We've got to a semi-final, nothing more."
Middlesbrough could have had few complaints had Cardiff extended their quickly-established two-goal advantage before the interval. For the first goal, Peter Whittingham's neat drag-back saw him easily evade Fabio Rochemback and another three men clad in red stood off and admired as the midfield player curled his seventh goal of the season into the top corner, via the post.
It was the first FA Cup goal Middlesbrough had conceded in 381 minutes of play and worse was to follow when Roger Johnson doubled Cardiff's lead shortly afterwards.
Emanuel Pogatetz, usually such a diligent marker, for once neglected his duties as Whittingham's free-kick floated into the box and Johnson, with an inch-perfect run, made the most of his freedom to plant an angled header past Mark Schwarzer and into the corner from six yards.
In between, an unmarked Jimmy Floyd Hasselbaink was guilty of heading wide at the near post from Tony Capaldi's inviting cross and Johnson, from another Whittingham free-kick, should have repeated his earlier goal-scoring feat.
An angled drive from Afonso Alves forced a fine save from the Cardiff goalkeeper, Peter Enckelman, but that was about it from Boro. "It was a big opportunity for us, but we can have few complaints, we were beaten by the better team," said Southgate.
Not even a rousing call from Jeff Winter, the referee-turned minor local celebrity who conducted the half-time draw and boldly predicted "3-2 to the Boro", could spark a Middlesbrough comeback like those which were commonplace on their journey to the 2006 Uefa Cup final.
Goals: Whittingham (9) 0-1, R Johnson (22) 0-2.
Middlesbrough (4-4-2): Schwarzer; Young, Huth, Wheater, Pogatetz; O'Neil (A Johnson, 57), Rochemback, Arca, Downing; Alves (Mido, 46), Sanli. Substitutes not used: Turnbull (gk), Boateng, Grounds.
Cardiff City (4-4-2): Enckelman; McNaughton (Blake, 88), R Johnson, Loovens, Capaldi; Rae, Whittingham, McPhail, Ramsey; Parry (Sinclair, 83) Hasselbaink (Thompson, 77). Substitutes not used: Oakes (gk), Purse.
Referee: M Dean (Wirral).
Booked: Middlesbrough O'Neil, Huth. Cardiff City Parry.
Man of the match: Whittingham