Sheffield United were frustrated by Brentford as the play-off chasing Blades were held to a 1-1 draw at Griffin Park.
The Blades took the lead just after the break when Chris Basham netted past Bees keeper Daniel Bentley. The game exploded into life on 68 minutes when 20-year-old Chris Mepham equalised with his first goal for the Bees, rifling home a low drive through a forest of legs after United failed to clear.
As he celebrated by the corner flag, Brentford midfielder Ryan Woods tried to grapple the ball from keeper Jamal Blackman and both were shown straight reds after lashing out during the tussle.
The dismissals added spice to a game that was dictated by the atrocious conditions caused by the torrential rain that fell across the whole 90 minutes.
Honours were even in a cat-and-mouse first half and Brentford's Denmark international right-back Henrik Dalsgaard had the first effort on goal after 13 minutes, but his sizzling 25-yard strike was tipped wide at the foot of a post by Blackman.
Nico Yennaris should have done better for the hosts when the ball sat up perfectly on the edge of the box, but he sliced his first-time shot from the edge of the box well wide.
The Blades always looked a threat going forward, and a sweeping move 20 minutes in ended when Basham's drilled low cross was volleyed wide at the far post by Billy Sharp.
John Fleck tested Bentley with a dipping drive from just inside the box before Brentford went up the other end, where Mepham's speculative effort was easily saved by Blackman.
United thought they had broken the deadlock just before the break when a fierce left-wing cross found Sharp, whose near-post volley was blocked at point-blank range by Bentley, who then pounced on the ball.
United looked the more direct side as the half wore on and their game suited the conditions better, with veteran striker Leon Clarke a constant threat.
United almost went in ahead at the break when Bentley's punched clearance dropped for George Baldock, but his attempt on goal drifted wide.
After the explosive start to the second half, Brentford had Bentley to thanks for a string of stops that kept his side in it.
First he denied United substitute and former Bee Clayton Donaldson with a brave save and then thwarted Clarke with an almost carbon-copy block after his slaloming run past three waterlogged Bees defenders.
Neal Maupay's 82nd-minute effort lacked the power to test another former Brentford man Simon Moore, who replaced Blackman after the double dismissal.
United continued to press for the winner to the end and only another reflex Bentley stop kept it level as Donaldson bore down on goal.