Macclesfield Town were unable to recreate the magic of last month's FA Cup win over holders Crystal Palace, with a Sam Heathcote own goal sending Brentford through to the fifth round after a spirited contest at Moss Rose.
Premier League side Brentford sat 116 places above the National League North team at the start of the evening - one less than the Palace side who were famously humbled by Macclesfield in the third round - but the gulf between the teams was turned on its head as John Rooney's part-timers dominated the first half.
A Bees side showing seven changes could not match the will or the skill of a Macclesfield team with a taste for giant-killing and the promise of a fifth-round trip to West Ham awaiting.
But they were not quite able to steal a lead before the break and failed to keep their fierce tempo as the game progressed.
Keith Andrews' team were far from top-flight standard but they set up camp in the final third and probed until something fell their way. It came in the 70th minute, Aaron Hickey finding space on the left and firing in a cross which the unlucky Heathcote glanced agonisingly past his own keeper.
Macclesfield dominated the first period, were first to every ball and bristling with an intent that their more glamourous opponents could not come near. The only thing they failed to do was find the net.
The tone was set instantly, less than a minute gone when Isaac Buckley-Ricketts won a free-kick, which Paul Dawson headed over. Both men were scorers against Palace and came ready to repeat the feat.
Brentford's altered XI, meanwhile, looked slow and disjointed, hurried and hassled by the home side. Luke Duffy was doing a particularly good job of squeezing their space and collected one horribly ill-judged pass across the edge of the area before firing over.
Yehor Yarmolyuk had his pocket picked by the double act of Duffy and D'Mani Mellor in the 18th minute, earning Dawson a clear sight of goal. The skipper lined up a drive from 20 yards but saw it skim agonisingly wide as the atmosphere cranked up a notch in response.
The Bees were timid by comparison, frequently looking for Romelle Donovan's quick feet on the right but struggling to do better than a goalmouth scramble and a wayward header from debutant Kaye Furo, a recent arrival from Club Brugge.
Their error count rose again when Vitaly Janelt slipped under pressure from Duffy and dragged him down with space opening up behind him. A yellow card followed but he may have spared his side much worse.
A rare break from Brentford saw Max Dearnley save well from Reiss Nelson, but the half-time stalemate flattered the visitors.
The tempo shifted after the restart, Brentford causing problems from back-to-back corners and seeing two teasing crosses go unconverted as they finally exerted some pressure.
The corners kept coming as Macclesfield were penned back, one coming when Mathias Jensen's chipped pass into the box kept going and forced Dearnley to tip over.
A moment of indecision from goalkeeper Hakon Valdimarsson almost let Macclesfield substitute James Gale in, but moments later the decisive goal arrived. Hickey burrowed in down the left and fired in his cross, only for Heathcote to make first contact and flash a header into his own net.
The crowd roared in the hope of an equaliser, as a failed penalty claim for handball against Michael Kayode came to nothing.
When Mellor found a good position inside the box, two brave blocks prevented the fairy tale from stretching into extra time but a harsh second was averted when Brentford squandered a breakaway in the closing seconds.
Macclesfield boss John Rooney:
"I couldn't be any prouder. Days like this are why you are involved.
"It's an unbelievable touch by their manager to come into our dressing room after full-time. He spoke highly of us. Of myself, the players, and the thing he saw was a real togetherness we had about us.
"We're a close-knit group and in football I think that takes you a long way. I'm proud to go and replicate the Crystal Palace performance. For a club of our level to go toe to toe with two Premier League teams is incredible."
On Heathcote, who looked distraught after unwittingly providing the decisive touch, Rooney said: "All the lads are a little bit down and Sam's the same.
"That's natural, they've just lost a football match and it will take a little time but they all know what they've achieved."
Brentford boss Keith Andrews:
"I've a lot of respect for the way they play and the spirit they have, it was very impressive.
"[I told them] what respect I have for what they've achieved, the journey they've been on. I love the English football pyramid, I've played in a lot of it and I've coached in a lot of it. I love what it stands for.
"This club is on a really good journey and I love stories like that. It fills my heart. They were immense and they gave us a proper cup tie that most people would have enjoyed… but I can't say I did!
"Arsenal to Macclesfield… it's a big shift, for sure. There's no point saying otherwise, because the facts are that Arsenal are top of the Premier League and Macclesfield are level six, so it's a huge shift.
"Your mentality gets tested and it's a very different type of game - everyone bar Brentford fans wanted us to lose and that's very different for us."
