Brentford were gifted an opening goal in the 22nd minute when Whites keeper Andy Lonergan dropped a cross from Romaine Sawyers allowing Neal Maupay to head home and the Bees squandered a fine chance to double their lead shortly before the break when Ollie Watkins lashed a penalty over the bar.
Leeds drew level in the 67th minute when Daniel Bentley mirrored the antics of Lonergan by dropping a cross from Gaetano Berardi which allowed Gjanni Alioski to head home.
But Brentford’s Yoann Barbet curled home a low free-kick from the edge of the area in the 85th minute and the Bees added a third in stoppage time through Ryan Woods.
Leeds were fortunate to survive in the second minute when Watkins almost converted a hanging cross from Nico Yennaris.
Barbet then sent a free-kick just wide and Lonergan then saved a stinging drive from Watkins.
Leeds took 16 minutes to muster an attack through Samu Saiz who saw his shot blocked before Alioski’s effort from the edge of the box was saved.
But Brentford were handed an absolute gift of an opening goal after a horlicks from Lonergan in the 22nd minute.
Sawyers delivered a cross from the left flank but Lonergan dropped the ball and Maupay had the simple task of heading into an empty net.
United should have equalised in the 38th minute when Lonergan’s long punt played in Pierre-Michel Lasogga one-on-one but the German’s attempted lob sailed over.
But Brentford were then handed a golden chance to double their lead when a late tackle from Jansson on Maupay gave the Bees a penalty.
Watkins took the spot kick but spectacularly blazed his effort over the crossbar.
Whites head coach Thomas Christiansen hauled off Lasogga and Eunan O’Kane during the interval as Kemar Roofe and Pablo Hernandez were sent on and Leeds made a bright start to the second half.
From a fine cross from Berardi, Alioski put a close-range header over.
But Brentford remained a threat and Watkins saw his superb effort in the 59th-minute hit the crossbar.
Leeds then upped the ante and after Ronaldo Vieira’s drive produced a fantastic save by Bentley, the Brentford ‘keeper then followed the earlier antics of Lonergan by dropping a cross.
Berardi supplied the delivery which Bentley spilled, allowing Alioski to head the bouncing ball home.
Saiz then drilled a low effort just wide before Liam Cooper narrowly failed to convert a Hernandez free-kick with a flicked header.
Brentford were then denied by the crossbar for the second time in the 79th minute through a long-range thunderbolt from Yennaris.
Yet Barbet smashed home a free-kick from the edge of the area with five minutes left after Kalvin Phillips had fouled Florian Jozefzoon.
Leeds had just one last chance to bag an equaliser but Luke Ayling headed just wide from a Hernandez free-kick in the final minute.
And Brentford rubbed further salt in United’s wounds in the final minute of stoppage time when Woods fired home into the far corner amidst a defence in disarray.
Leeds United: Lonergan, Ayling, Cooper, Jansson, Berardi, O’Kane (Hernandez 45), Phillips, Vieira, Alioski (Grot 80), Saiz, Lasogga (Roofe 45). Subs not used: Wiedwald, Shaughnessy, Dallas, Sacko.
Brentford: Bentley, Bjelland (Mepham 45), Jozefzoon, Yennaris, Maupay (Vibe 80), Watkins, Egan, Woods, Sawyers (Mokotjo 73), Clarke, Barbet. Subs not used: Daniels, Macleod, McEachran, Canos.
Referee: Stuart Attwell.
Good Day For:
Brentford’s momentum. They are one of the form teams in a division where so many sides struggle to maintain confidence and their confidence was in contrast to so much of United’s display. There was fight and passion from Leeds in the second half but the result went the way which recent scorelines said it would. Christiansen is up against it now.
Bad Day For:
Andy Lonergan. Plenty of criticism was aimed at Felix Wiedwald earlier in the season but Lonergan’s first-half mistake at Griffin Park was as bad as any of the German’s. It was genuinely the last thing Leeds needed with the pressure already on. Bentley returned the favour in the second half but when Barbet’s free-kick crept inside Lonergan’s far post, it was game over.
Brentford’s second goal. The game was on a knife-edge at that stage and by the time Yoann Barbet’s free-kick flew in, it was a case of next goal wins. Should Lonergan have done better with it? Probably.