Read a full match report of the FA Cup third-round game between Aston Villa and Sheffield United at Villa Park on Saturday Jan 4, 2014.

Paul Lambert ought to be careful what he wishes for. The screeches of discontent that followed this wretched embarrassment for Aston Villa were as loud as they were sustained, prompting the manager to think twice about the wisdom of denigrating the FA Cup’s value.

His suggestion last week that Premier League clubs tended to regard the competition as an inconvenience was sadly mirrored in the performance of his players, humiliated by League One’s Sheffield United, for whom an exquisite late Ryan Flynn strike rewarded their manifest desire to win.

Fifty-one league places separated the sides, but never did Villa come close to emulating their opponents for perseverance or pluck. Instead they reflected their billing as a team who had only won twice at home all season, undone by Jamie Murphy’s deflected opener and Flynn’s extraordinary late flourish.

Looking befuddled about how to break down United’s well-marshalled defence, they succumbed to a deserved defeat, which Lambert might have perceived as one less complication but to which the club’s entertainment-starved fans responded with anger and indignation.

Martin O’Neill once made this mistake of under-estimating a trophy’s value, throwing away Villa’s chances of progress in the 2009 Europa League when he fielded a shadow side against CSKA Moscow.

Lambert at least dignified the FA Cup with an ostensibly powerful line-up, which included star striker Christian Benteke, although his intimation that the match was a low priority was hardly the most sensitive message to have imparted to his players.

United, by contrast, attacked their task with passion, as manager Nigel Clough celebrated another fabulous FA Cup result after the famous 0-0 draw in 2004 with Manchester United when he was in charge of Burton Albion. The Cup, let us not forget, is the one prize that forever eluded father Brian.

Lambert had attempted to minimise the damage of his pre-match remarks when he described the FA Cup as a “sometimes welcome respite and an opportunity to establish and maintain some momentum.”

But the impression that a victory was not uppermost of Villa’s targets this campaign was self-evident from the outset. Their sluggishness was punished swiftly, when United punished some poor marking, Murphy beating Matthew Lowton before drilling a right-foot shot that took a heavy deflection off captain Ciaran Clark and into the net.

One had to sympathise with second-choice goalkeeper Jed Steer, making a rare appearance in place of Jed Steer, as the 6,000 travelling supporters erupted in joy.

Christian Benteke betrayed the ill-effects of his month out with a calf injury, with two abject aerial misses as Villa laboured for an equaliser on the stroke of half-time. First the Belgian, not exactly World Cup material on this evidence, headed wide from an Albrighton chip and then two minutes did exactly the same, even after the ball had been served up on a platter by his strike partner.

United were visibly tiring from their earlier exertions, but roused themselves early in the second half when Ryan Flynn’s fierce drive was smartly parried by Jed Steer.

Despite Villa’s fleeting incursions, not least when Albrighton’s overhit cross almost embarrassed goalkeeper George Long, United appeared for extended spells to be the likelier team to score.

Flynn, cutting inside from the right, easily skipped past Antonio Luna to let fly with a strike that troubled Steer, before centre-forward George Porter combined deftly with Jose Baxter, only for his shot to drift narrowly wide of the near post.

Villa fans howled in protest as their team stroked the ball around lethargically, and only when 6ft 5in striker Nicklas Helenius replaced the ineffectual Aleksandar Tonev was the requisite urgency injected. Instantly the Dane energised the attack, and as United toiled to defend a succession of corners their resistance folded.

Initially Benteke’s effort was saved but the 22-year-old Helenius, starved of first-team opportunities, swivelled in a flash to angle his shot below the sprawling Long.

The home side celebrated as if they had just won the Cup, yet complacency swiftly set in. United had an immediate chance of a riposte as Baxter surged clear on the left, before he contrived to aim his attempt straight at Steer.

When Flynn flashed another shot across the face of goal it seemed that the opportunity had gone, but it turned out he was saving up his coup de grace. Seeing no options on either side he chose to shoot with his weaker left foot and caught it exquisitely, watching the ball fly beyond Steer and straight into the top corner.

Jubilation engulfed the Sheffield end, although there were to be further alarms as United sought to play down the clock with all 11 bodies behind the ball.

Benteke shaped himself to deliver a spectacular overhead kick in added time but the ball sailed harmlessly over. Clough, gesturing like a man possessed to the referee to sound his whistle, could bask in one of his finest hours.

For Lambert, the inquest was only just beginning.