Emyr Huws gave Town a 26th minute lead but Nico Yennaris equalised a minute before half-time to leave the Blues’ home game with Brentford level at 1-1 at the break.
Top scorer Tom Lawrence returned after his two-match ban to an otherwise unchanged Town side with Freddie Sears dropping to the bench.
For Brentford, Lasse Vibe was back from injury and came into the attack for Konstantin Kerschbaumer, who was on the bench with Romaine Sawyers switching to midfield, while Sergi Canos took over from Florian Jozefzoon.
The Bees started very brightly, Yennaris finding Sergi Canos with a raking pass in the opening minute but Blues skipper Luke Chambers got a cross to block.
The corner came to nothing but the visitors continued to make the early running and soon afterwards Chambers was forced to turn the ball behind as Canos sought to cut back from the byline. ""From the flag-kick Jordan Spence blocked Maxime Colin’s strike, then a subsequent Jota effort also found a Town defender in the way.
The Blues threatened for the first time in the seventh minute when Christophe Berra and Jonas Knudsen both rose high but the ball was diverted the wrong side of the post.
On 10 Lawrence was fed through on goal but Bees keeper Daniel Bentley saved and the flag had been raised in any case. Soon after, the on-loan Leicester man hit a cross-shot from the left which flew wide.
After Brentford’s early pressure Town had got more into the game and were looking the more dangerous side, although without having forced Bentley into a serious save by that stage.
In the 19th minute Lawrence cut in and hit a shot from the left which was blocked, then a defender took the loose ball away from Spence just inside the box.
But on 26 the Blues went in front and as against Norwich last week following a long spell of passing.
Eventually Huws tapped the ball wide to Lawrence on the right from where the Leicester loanee looked to cross deep into the area. However, he hit it straight at the on-loan Cardiff man, who took it down and hooked his second goal for the club past Brentford keeper Bentley, who had been caught unawares.
There was a big scare for the Blues in the 35th minute when Chambers was caught in possession on halfway by Canos and the Bees broke through Vibe. However, Berra did superbly to block the Dane’s first strike and then Sawyers’s subsequent effort from the edge of the box.
As half-time approached the visitors put the Blues under a sustained spell of pressure and in the 44th minute they levelled when Sawyers played a clever ball in behind the Town defence for Yennaris, who burst into the box and beat the advancing Bartosz Bialkowski.
The Blues had one opportunity to restore their lead in the moments before the break but Berra headed Lawrence’s freekick from the right wide.
The Bees had deserved their equaliser shortly before half-time having been in charge and probing for an opening for a number of minutes prior to Yennaris’s goal.
Having repelled the visitors’ early pressure, Town had got themselves into the game and had got on top by the time Huws got his goal, although while rarely playing particularly fluid football, before allowing Brentford to get back in charge in the spell in which they scored their goal.
Town: Bialkowski, Spence, Chambers (c), Berra, Knudsen, Kenlock, Skuse, Ward, Huws, Lawrence, McGoldrick. Subs: Gerken, T Smith, Pitman, Bru, Sears, Moore, Diagouraga.
Brentford: Bentley, Colin, Bjelland, Yennaris, Egan, Woods, Sawyers, Vibe, Henry, Jota, Canos. Subs: Bonham, Jozefzoon, Kerschbaumer, Clarke, Barbet, Cole, Shaibu. Referee: Scott Duncan (Northumberland).