Derby County fell to their second consecutive Sky Bet Championship defeat as Stuart Dallas struck an injury time winner for Brentford at Griffin Park.
Chris Martin scored his 12th goal of the season midway through the first half, but from then on, the home side’s energy, persistence and attacking qualities shone through.
Four minutes after the interval, Andre Gray grabbed an equaliser and Dallas struck deep into injury time to leave Derby deflated.
Quick and full of intent, both sides made bright starts to the contest as they spread the ball across the pitch, but it was the Rams who worked the first opening of the contest.
First came the skill and movement from Dawkins and then the hard work as he evaded a number of challenges before lashing a left foot effort into the side netting of David Button’s near post.
A low cross from Forsyth, after the full back had been set free in the area, narrowly evaded another Rams attacked, before Chris Martin curled a long range effort well over the bar.
As the game entered past the 18th minute mark, as Richard Keogh rose highest to connect with Johnny Russell’s corner. The Captain diverted the goal bound and after being flicked on by Jeff Hendrick, the ball was smashed clear by Toumani Diagouraga.
Derby, though, began to assert their dominance and after Cyrus Christie had robbed Brentford of possession, he fed Forsyth down the left hand side whose first low cross was turned into the far corner by Martin after 27 minutes.
A free flowing move forward, again started by Christie, saw the ball switched from right to left as Hendrick carved out space on the left. The Republic of Ireland nodded the ball into the path of Martin, whose touch let him down as he tried to round the ‘keeper.
Omar Mascarell and Hendrick both had efforts deflected for a corner with just under 10 minutes of the half remaining as Derby continued to pile on the pressure, but in a rare break forward, Brentford nearly equalised.
Lead by Jota, Brentford poured forward and the Spanish midfielder picked out Jon Toral on the left side, but his chipped effort sailed harmlessly wide of Jack Butland’s goal.
The home side piled on pressure as the game petered out to half time without significantly troubling Butland in the Rams’ goal, but it took until four minutes after the restart to make the break through.
Another sweeping move forward from the home side saw the ball fall to the feet of Andre Gray, who curled an excellent first time effort beyond the outstretched finger tips of Butland and into the back of the net.
With the bit between their teeth, Brentford continued to control and dictate the rhythm of the contest, but following the introductions of Will Hughes and Jordon Ibe, Derby fought their way back into the contest.
A dangerous ball into the box by Christie narrowly missed the outstretched legs of both Russell and Martin as the game passed the hour mark, before the post came to Derby’s rescue.
A long punt up field was well controlled by Alan Judge and after stepping inside Christie, the midfielder chipped a delicate ball into the six-yard area for Gray, whose headed smashed the foot of Butland’s far post.
Up the other end, Ibe cracked a left foot effort into the midriff of Button and on 72 minutes, Martin directed another Christie cross from the right into the arms of the ‘keeper.
As time ticked down, both teams continued to spar without creating any clear-cut opportunities. Christie blasted an effort goal wards that was blocked by two defenders throwing their bodies on the line, before the home side knocked the stuffing out of McClaren’s side with a late winner.
Substitute Stuart Dallas took up a position on the left hand side and as the ball was worked from the right the ball fell to the feet of the winger, who curled in an injury time winner that left the Rams no time to reply.
Brentford: Button, Tidwell, Craig, Dan, Douglas, Odubajo, Toral (Dallas, 65), Judge, Gray (Proschwitz, 73), Diagouraga, Jota (Pritchard, 65)
Substitutes not used: Bonham, Saunders, Tarkowski, Smith
Derby County: Butland, Christie, Keogh, Buxton, Forsyth, Mascarell, Bryson (Hughes, 57), Hendrick, Russell (Coutts, 77), Dawkins (Ibe, 62), Martin
Substitutes not used: Roos, Eustace, Best, Shotton
Attendance: 10,608 (1,705 away fans)