Dan Sparkes was the hero for non-league Barnet after his stunning second-half free-kick forced a replay against Brentford following a 3-3 FA Cup thriller at the Hive.
Ollie Watkins scored the opener for the Championship side in the opening period before Shaq Coulthirst scored a brace in three second-half minutes to put the National League side ahead.
A controversial penalty enabled Brentford to get back into the tie before Sergi Canos gave the visitors the lead.
But Sparkes provided a moment of magic in a pulsating tie to keep the lowest-ranked team in the competition and earn a replay against opponents three tiers higher in the English football pyramid.
Barnet saw off Championship side Sheffield United at the last stage, and on Monday faced another side from England's second tier – also playing in red and white – as they aimed to reach the fifth round for the first time in their history.
Emboldened by a record crowd at a home they have called their own since 2013, Barnet began the game on the front foot.
But it was their opponents who began to take control, rattling the frame of the goal twice.
First Yoann Barbet thought he had scored, only to see his header crash off a post.
Then, midway through the opening period, Brentford right-back Moses Odubajo cut in from the touchline and unleashed an unstoppable strike from distance, but a post intervened again.
Barnet defender Dan Sweeney had played a starring role for the hosts to keep the score level and, at the other end, brought Luke Daniels into action for the first time. Leaping highest from a corner, his bullet header was turned away by the Brentford goalkeeper.
Sweeney's chance kick-started a brief spell of domination for the hosts, only for Brentford to land what seemed a sucker-blow with just five minutes of the half remaining.
Watkins drifted inside on his right before unleashing a 25-yard curling effort that left goalkeeper Will Huffer diving in despair.
"There's only one Bees in London," sang fans of Brentford, who share the same nickname with Barnet, as the Championship side took a slender lead into the interval.
Yet, within five minutes of the second half, it was the home support suddenly in full voice.
Ephron Mason-Clark was the provider on the right-hand side, twisting and turning before finding Coulthirst, who toe-poked home.
Coulthirst, whose goal saw off the Blades in the previous round, slid on his knees, and it was not long before he was dramatically celebrating his second.
Following a desperate scramble in the Brentford box, the ball fell to the striker who again made no mistake to make it two goals in 192 seconds.
On the hour mark, this compelling tie took another twist when Brentford were awarded a controversial spot-kick.
Watkins fell in the area, but TV replays suggested there was no contact from David Tutonda.
With no VAR available, the penalty stood and Neal Maupay sent Huffer the wrong way.
The non-league side had every right to feel hard-done by, and their misery would be compounded when Canos then scored a fine breakaway goal.
But Sparkes struck to get Barnet level again as the substitute somehow managed to get his free-kick up and over the ball and into the back of the net.
The visitors went in search of a winner, with Daniels denying Maupay and Odubajo hitting a post for a second time on the night, but Barnet hung on to force a replay, with a trip to Championship side Swansea awaiting the winners.