Clayton Donaldson scored a late winner as Brentford booked a place in the FA Cup with Budweiser Fourth Round and set up a game against holders Chelsea.
The Bees finally overcame Southend United in a Third Round Replay thanks to Donaldson’s 18th goal of the season, scored with 14 minutes remaining.
Southend started brightly – Simon Moore got down well to save from Anthony Straker and also smothered at the feet of Barry Corr.
But the visitors were soon up against it, Brentford’s midfield dominated proceedings and it seemed as if goals were only a matter of time.
Brentford laid siege to the Southend goal for most of the match and the visitors were only still in the game thanks to a magnificent performance from goalkeeper Paul Smith.
He could do nothing to prevent Paul Hayes scoring from close range in the first half but produced save after save, including one from a Harry Forrester penalty that defied belief.
It looked as if that master class would keep his team in the cup when Corr equalised but Donaldson found the winner and Brentford will now take on Chelsea on Sunday January 27.
Pre-match talk may have been of the prize but the game itself was the Paul Smith Show.
He made a low stop from a Harry Forrester effort and an even better one when Donaldson met a Lee Hodson cross on the volley.
Forrester also shot wide after a run from deep and then smacked the crossbar with a fizzing effort before Donaldson had a shot blocked.
There was almost a chance a minute as the game ticked towards the one quarter mark – Smith turned away an Adam Forshaw cross that beat everyone and seemed set for the bottom corner and Hayes flicked a header wide.
Toumani Diagouraga missed the target with a volley and a Harlee Dean header was blocked before the breakthrough came 26 minutes in.
Southend could not clear their lines after a series of corners, Hodson delivered from the right and Hayes stole in to volley home at the far post from point blank range.
The visitors almost stole an equaliser when Straker’s header was pushed on to the crossbar by Moore and the wide man then knocked the rebound wide.
But that would have been incredibly unjust, the chances continued to come at the other end and Smith continued to thwart his former club.
He pushed away a Forrester shot after a slaloming run that saw him beat three or four men and when Donaldson bundled his way past the Southend defence, Smith again pushed the shot away.
Forrester had a shot blocked; Hayes fired wide and then brought another fine save out of Smith when he connected firmly with a low Forshaw free kick.
Smith pushed a Forshaw shot over and when the Brentford midfield player exchanged passed with Hayes and fired across goal, the Southend stopper not only palmed it away but managed to divert it out of the path of the arriving Donaldson.
Donaldson and Forshaw both had shots blocked at the end of the first half and Southend would have been happier to have heard the half time whistle.
And the visitors started the second period brightly.
They should have levelled when Straker chested down a Kevan Hurst cross and Michael Timlin shot wide from ten yards.
Hurst also had a shot blocked for the League Two side but Brentford soon regained the initiative.
Hayes flicked a header from a Forshaw free kick inches wide and Smith saved at full stretch from a Forrester lob.
The goalkeeper was reminding the Brentford fans of his ability and produced a penalty save for the ages soon after.
Referee Darren Drysdale awarded the spot kick when Donaldson tricked his way in to the box and Sean Clohessy clipped his heels.
Forrester stepped up and blasted his penalty towards the top corner only to see Smith get up and push it wide of the post.
That may have given the visitors hope, but it did not alter the flow of the game.
Smith kept out an effort from Hayes and then denied Jonathan Douglas with his feet before Mark Phillips blocked Forrester’s follow-up.
The Southend goalkeeper saved a low Forshaw shot and then did even better to go full stretch and deny the same man – the livewire midfield player also had a shot blocked.
A powerful Douglas free kick was blocked and Forrester fired over as Brentford continue to dominate almost exclusively, without getting the second goal that would give them breathing space.
And Southend punished them with 21 minutes remaining.
Substitute Ryan Leonard picked up the ball and with his first touch sent over a cross for Corr to head his third goal of the tie, after he scored two in the 2-2 draw first time out, from close range.
It would have been easy for Brentford to sit back and feel sorry for themselves, having dominated for so long only to be pegged back, but they set about regaining their lead.
Donaldson headed a Jake Bidwell free kick over and Smith palmed away a Forrester shot.
The Bees regained the lead inside the final 15 minutes – Forshaw set Donaldson away in the inside right channel and he fired past Smith, possibly with the aid of a deflection, to again give Brentford the upper hand.
Marcello Trotta fired in to the side netting for The Bees but the chances dried up as the minutes ticked by.
The late onslaught that may have been expected from Southend never really materialised – Moore held a looping Leonard header but that was it and Brentford booked their date with Chelsea.
Brentford: Moore; Hodson, Dean, Craig, Bidwell; Forshaw (sub Saunders 90 mins), Douglas, Diagouraga, Forrester (sub Barron 80 mins); Hayes (sub Trotta 75 mins), Donaldson
Subs (not used): Gounet, Logan, Pierre, Reeves
Southend United: Smith; Clohessy, Cresswell (sub Woodyard 48 mins), Prosser, Barker; Phillips; Hurst (sub Leonard 68 mins), Timlin, Straker (sub Harris 89 mins); Corr, Tomlin
Subs (not used): Bentley, Martin, Benyon
Attendance: 6,526 (1,271 away fans)
By Chris Wickham