Barnet brushed Sheffield United aside in a Cup shock that was as comprehensive as it was totally unexpected.
The non-Leaguers made a nonsense of the 83 places separating the sides to reach the fourth round for the third time in their history.
It was a triumph for Darren Currie over his uncle Tony Currie, the Blades legend who watched his nephew's side prevail. Darren is unbeaten as Barnet's caretaker boss and looks now to have earned the job full time.
The margin could have been wider than Shaquile Coulthirst's first half penalty.
Although Blades boss Chris Wilder made ten changes it was still a side packed with experience.
Only one serious save was demanded of Bees keeper Mark Cousins as he tipped a Leon Clarke header onto the bar late on.
Barnet, mid-table in the National League, are currently 106th in the football pyramid. The Blades are 23rd, pushing the Championship's top two for automatic promotion to the Premier League.
While Barnet's hopes of breaching the 83 place gap were remote, they had reached the fourth round twice before - in successive years, 2007 and 2008. Eleven years on, the little London club is in something of a trough after relegation from the EFL last season.
It's also a transition period following the much respected John Still's step down from first team control. But that opened an exciting adventure for caretaker Darren Currie, unbeaten in his opening two games and facing his legendary uncle's team here.
Blades icon Tony Currie is now a director of the club and the main stand bears his name. This first meeting between these clubs had Barnet threatening a surprise from the start. They had already troubled United on several occasions before taking a merited 21st minute lead.
Scorer Coulthirst was the creator, cleverly playing in Ephron Mason-Clark who was tripped by Richard Stearman. Coulthirst buried the penalty via Simon Clark's fingertips for his sixth goal of the season.
With Medy Elito also a lively raider, a sluggish United were second best on and off the ball in the opening half. Only Paul Coutts, with a 20 yard volley, troubled Barnet, who also had an effort ruled out offside when Coulthirst netted an early header. Currie's side could and should have gone further in front straight after the break.
It took a vital interception from Martin Cranie to prevent an open goal for Coulthirst and then Dan Sweeney somehow missed point blank from a corner. The only change in United was the absence of manager Wilder's woolly hat.
Maybe he blew it off with his half-time hairdryer. Wilder was first to bring on two players he would have preferred to leave resting on the bench in Mark Duffy and Billy Sharp. One of few chances was wasted by Kieron Freeman.
