The ends can justify the means and, for Millwall, they certainly did. One hundred and eighty minutes of forgettable football matter not now. What does is a trip to the national stadium next month and a status as the Football League's surprise semi-finalists in the FA Cup.
Wembley should witness a clash of styles in the semi-final, with Millwall's rough-and-ready methods contrasting with Wigan's more aesthetically pleasing approach. In the truest FA Cup tradition, it is the Crazy Gang against the Culture Club, opposites pitted against each other for a prize.
Only Wigan stand between Millwall and a second final in a decade that, like the first, would probably result in European football. Given the right draw, there could be the incongruous sight of Inter Milan at the Den in autumn. That, however, is getting carried away, a crime the resolutely level-headed Kenny Jackett is unlikely to commit.
"We need to make sure we stay up now," he said. One strange possibility is that Millwall, who have only taken three points once since New Year's Day, play in the Europa League and League One next season. Rather more bluntly, Jackett's assistant, Joe Gallen, said: "Our league form is pretty alarming. We are sliding down the table fast."
So are Blackburn, which is one reason Ewood Park was largely unoccupied for a game of this magnitude. If few FA Cup quarter-finals can have had a smaller crowd, with a mere 8,635 paying to attend, still fewer can have had a more fitting winner. Given the diet of direct football in both games, a giant central defender was always going to be a dominant figure and 180 minutes of thud and blunder was determined by a thumping header from Danny Shittu.
It was both crucial and controversial. The preceding corner, taken by Chris Taylor, was incorrectly awarded when his shot went into the side-netting without taking a touch. Yet seconds earlier, Millwall had a plausible penalty appeal rejected when Dany N'Guessan's shot hit Jason Lowe's raised hand. Perhaps two wrongs made a right. Either way, it was the first, and indeed last, goal Blackburn conceded in the FA Cup this season.
"To lose to a set-play makes it even harder to take," Rovers manager Michael Appleton said. "We have lost an opportunity that the majority of us will never get again."
They were knocked out without a whimper. But exits are a theme at Ewood Park, with Danny Murphy being given a none-too-subtle hint that he should take his leave. There was no place on the bench for the deposed captain, despite the absence of seven injured and two cup-tied players. Instead two untried teenagers were named among the replacements.
Although one of them, Anton Forrester, was summoned for his debut in the search for an equaliser, and mediocre as Murphy has been for Rovers, it seemed unnecessarily petty by Appleton. "I don't think Danny is going to make much impact as a substitute," the manager said, unconvincingly. "We need to move forward as a football club."
Yet it was made all the more bemusing as, with the slow, ageing Murphy persona non grata, two slow, ageing players were paired in the centre of midfield. Admittedly, the seasoned campaigners, Morten Gamst Pedersen and David Dunn, were responsible for a rare moment of invention, the Norwegian baffling Millwall with a clever corner and the Englishman whipping a shot narrowly wide. That apart, however, few showed the nous to pick a pass. Rovers are devoid of inspiration and although Appleton has outlasted his unlamented predecessor, Henning Berg, dissent is growing.
Blackburn left the pitch to a chorus of boos having failed to score for the fifth time in six games. They came close only when Shane Lowry recovered superbly to hook Leon Best's shot off the line, denying the striker a goal on his belated home debut. "I can't ask any more from an effort point of view," Appleton added. "From a quality point of view, we could have been better."
That is an understatement. It is an issue, he thinks of both quality and mentality. "For two or three years, it has been almost acceptable to lose," he added. "For some of the players, it doesn't hurt as much as it should do."
But pain has become a constant at Ewood Park. It has been a defining theme of two-and-a-half dreadful years and the antibiotics aren't working. Their suffering continues.
MAN OF THE MATCH: Danny Shittu. The captain has been a talisman in this FA Cup campaign, scoring in the fourth-round win against Aston Villa and helping Millwall keep back-to-back clean sheets against Rovers.
BLACKBURN VERDICT: Unimpressive. A Wembley appearance would have meant they had salvaged something from a wretched season. Now there is no consolation. A club with a huge budget, by Championship standards, are not yet safe from the threat of relegation. But for Jordan Rhodes' goals, they surely would be in the bottom three and, over two games against Millwall, their star striker was starved of service. Injuries account for their plight but, given the size of their squad and their resources, they do not excuse Rovers.
MILLWALL VERDICT: Their league form has faltered since the loss of the prolific Chris Wood, who joined Leicester, but Jackett's men have displayed their resolve in the knockout competition. They are a side with little style but plenty of solidity. Taylor, one of the few to provide flair, offered some nice touches but the emphasis was on industry.