Brentford 3 Leyton Orient 1
Orient finished the game with 10 players after captain Jack Simpson was shown a second yellow for dragging down Kevin Schade.
Thomas Frank made three changes to the side that lined up against Colchester United in the second round.
Jayden Meghoma, a Deadline Day signing from Southampton, made his Brentford debut at left-back.
Mads Roerslev and Nørgaard also came in, with Vitaly Janelt, Keane Lewis-Potter and Frank Onyeka (on loan at Augsburg) the three to make way.
It took 10 minutes for Orient to create the game’s first opening. Jamie Donley’s pass ricocheted off a backtracking Ben Mee and the Tottenham loanee pulled wide from the edge of the box via the outstretched leg of Yehor Yarmoliuk.
Moments later, the visitors took the lead. After a spell of possession around the Bees’ box, James crossed first time from the right and Cooper ghosted in at the back post to turn home.
But Leyton Orient’s lead was short lived. Schade collected the ball midway inside the opposition half, charged beyond four defenders and saw his low drive pushed out by Josh Keeley. Carvalho, anticipating the rebound inside the six-yard box, was perfectly placed to beat the keeper with a superb acrobatic effort.
Midway through the half, Donley’s dipping effort from 25 yards was tipped over the crossbar by Hákon Valdimarsson.
On 26 minutes, Carvalho turned provider. The summer signing was given time and space to cut in and cross from the left. His deep delivery was met by Damsgaard, who headed beyond Keeley despite the scrambling keeper’s best efforts to make a save.
10 minutes later, James teed up Sonny Perkins 25 yards from goal and the forward’s rising effort sailed over the bar and into the west stand.
Simpson was then shown a yellow card for pulling down Schade as the forward looked to latch on to Nørgaard’s through ball and race through on goal.
The Bees extended their advantage in the final minute of the half. Meghoma’s looping cross from the left was only half cleared and Carvalho beat Lewis Warrington to the loose ball inside the box, nudging towards the advancing Nørgaard who stroked first time into the far corner from 20 yards.
In the first action after the break, Donley won and then delivered a corner. Simpson rose highest to meet the ball inside the box, but his header flew over the bar.
Just before the hour mark, substitute Charlie Kelman raced on to James’ ball over the top, advanced towards goal and forced Valdimarsson into a low save to his left.
Jayden Sweeney’s speculative effort from the left of the box flew well over the bar.
At the other end, after a flowing move from back to front, Yarmoliuk released Roerslev and the full-back drove powerfully into the side netting from just outside the box.
On 69 minutes, Orient captain Simpson was shown a second yellow card for cynical foul on Schade.
Carvalho’s low strike from the right of the box was saved by Keeley, before Schade immediately worked the ball to Damsgaard whose tame effort was held by the keeper.
On 82 minutes, Roerslev curled a cross into the box and Keane Lewis-Potter’s header was saved by Keeley. Moments later, the O’s keeper made a sprawling stop to deny Bryan Mbeumo who had advanced down the right and cut in on his left.
In the final seconds, Schade hung up a cross from the byline and substitute Toney Yogane headed wide.
Having secured their passage to the fourth round, Brentford must wait until Wednesday 25 September to find out their next Carabao Cup opponents.
Brentford: Valdimarsson; Roerslev, van den Berg (Ji-soo 76), Mee, Meghoma (Yogane 84); Nørgaard (Konak 62), Trevitt (Mbeumo 76), Yarmoliuk; Damsgaard (Lewis-Potter 76), Carvalho; Schade
Subs not used: Cox, Pinnock, Collins, Janelt
Leyton Orient: Keeley; James, Simpson, Cooper, Sweeney; Warrington; Donley (Agyei 72), Ball (Pratley 71), Obiero (Beckles 72), Jaiyesimi (Galbraith 54); Perkins (Kelman 54)
Subs not used: Hemming, Graham, O’Neill, Clare
Attendance: 13,634
Frank 'pleased' to be in the hat for next roundBrentford head coach Thomas Frank gave his thoughts on Tuesday night's win against Leyton Orient, and was delighted to get through to the next round of the Carabao Cup.
The Bees boss said: “It’s job done. I’ve said it many times: we want to go on a cup run, we want to go as far as possible and potentially win it - we know it’s difficult but that’s the aim.
“In these games, I need to find the perfect balance between putting a strong team out there, the mix of freshness but also with the game on Saturday in mind, and then also using the squad, because players need that to develop and also want to be included.
“We hit the level today; credit to Leyton Orient, they did well in the first 20 minutes, we didn’t get enough control, but then we got our goal, and from there we were in control.
“3-1 ahead at half-time; second half, I wanted us to be even more on top, but it’s not easy, they gave everything. But I'm pleased."
Carvalho: I know I’ve got the ability to do things like thatFábio Carvalho expressed his delight after registering a goal and two assists on his first start at the Gtech.
Asked about his overhead kick, he said: “I’ve done it in training but not in a game!
"My dad is going to be very happy! It’s about getting in the right areas at the right time and luckily it fell to me. I know I’ve got the ability to do things like that.”