Sergi Canos’ early opener, Julian Jeanvier‘s volley and Neal Maupay gave Barnet a mountain to climb before David Tutonda gave the National League side something to cheer about late on.
It was Brentford who saw more of the ball in the opening stages of the game and their pressure paid off on seven minutes. After Said Benrahma’s clever one-two with Josh McEachran from a corner, the former quickly whipped in a low ball which was tapped home by Canos from close range.
The Championship side were at it again soon after when Romain Sawyers found Moses Odubajo before the Brentford number two let rip from distance, narrowly missing the post. They attacked Barnet’s defence again only seconds later when Benrahma cut inside before unleashing a low drive from the edge of the box but could only find the side-netting.
Just before the quarter-of-an-hour mark, Barnet pushed for an equaliser. After Ephron Mason-Clark’s cross was cleared to Medy Elito, the Barnet number 21 curled an ambitious effort from distance, the ball flying high and wide.
Up the other end and Brentford were on the hunt for a second, this time through Neal Maupay. The Bees’ top scorer wriggled his way through the defence before his shot from close range deflected off Mark Cousins before Elliott Johnson did well to clear off the line.
Maupay caused more problems soon after when Henrik Dalsgaard floated in a delightful cross which was met by the Brentford striker but his header flew over.
The visitors were forced to make their first change of the game on 23 minutes when Johnson limped off, making way for Andre Boucaud.
Just before the half-hour mark and Barnet had Dan Sweeney to thank for temporarily putting out Brentford’s attacking fuse, calmly standing his ground and clearing his lines on multiple occasions.
However, the hosts did manage to double their lead moments later after Julian Jeanvier latched on to a Benrahma free-kick from the right flank, tapping home from close range.
Darren Currie’s side were nearly caught out by another free-kick four minutes before the break when McEachran whipped it in from the left but Canos’ down-ward header fell wide.
Barnet had a chance to pull one back two minutes before first half stoppage time though when Mason-Clark charged forward before feeding in Jack Taylor who struck first time but his low drive fizzed wide.
It was to be Brentford who would have the last chance of the half when Canos saw his effort from close range fly over Cousins’ bar.
HT – 2-0
Dan Sparkes, who was the hero of the initial tie, came on for Wes Fonguck at half-time in the only change at the break.
It proved to be a very heated start to the second period after a collision between Canos and Elito sparked a brawl which ended in the pair receiving a booking, alongside Sweeney for his reaction.
Brentford then attacked Barnet on the counter moments later after Canos did well to sprint down the left flank before feeding in Maupay but his shot was tipped around the post by Cousins.
The National League side had a great chance to half the deficit 10 minutes into the second half when they were awarded a free-kick after a foul on Shaq Coulthirst. Up stepped Sparkes, of course, but he couldn’t replicate last week’s heroics as he watched his curling effort narrowly float over the bar.
Maupay nearly extended his side’s lead just shy of the hour mark from close range before Sawyers missed two great opportunities to score aswell.
After Barnet were awarded another free-kick, Sparkes floated it in before Craig Robson headed over at the far post, missing the chance to add to his two FA Cup goals this season.
Currie’s men had another chance to pull one back minutes later when Mason-Clark cut inside before firing low and hard into the gloves of Daniels.
With just under 20 minutes remaining, Brentford made in 3-0 after Dalsgaard played in Maupay who tapped in before he was replaced by Marcus Forss. Chiedozie Ogbene also came on for the hosts in place of Benrahma whilst Simeon Akinola replaced Mason-Clark.
The North London side then pulled one back after Tutonda did very well to turn and blast the ball into the top corner from inside the box.
Substitute Ogbene nearly made an instant impact when he raced through on goal before firing low but it was comfortable enough for Cousins.
Another Sparkes free-kick nearly flew into the back of the net with five minutes to go after Mads Bech Sorensen was shown a yellow for committing the foul but his effort went over.
Barnet’s goal scorer Tutonda also picked up a booking in the final stages of normal time for a foul in a dangerous area, giving away a free-kick which came to nothing.
Brentford calmly kept possession in the five minutes that were added on and held on to book their place in round five where they will face Swansea City.
The Bees return to league action on Saturday afternoon, hosting Sutton United at the Hive London.
Brentford side: Daniels, Odubajo, Canos, Maupay (Forss), McEachran, Sawyers (DaSilva), Benrahma (Ogbene), Dalsgaard, Jeanvier, Konsa, Sorensen.
Unused subs: Bentley, Watkins, Mokotjo, Barbet.
Barnet side: Cousins, Alexander, Johnson (Boucaud), Robson (c), Coulthirst, J.Taylor, Fonguck (Sparkes), Elito, Tutonda, Sweeney, Mason-Clark
Unused subs: Matrevics, Harrison, Payne, Bettamer
Attendance: 6,954 (1,648 away fans)