James Maddison's free-kick earned a point for Coventry City in a fiesty Under 18 Professional Development League Two South encounter which saw both teams reduced to 10 men.
Joshua Bohui gave The Bees the lead with a composed finish after 10 minutes but that was cancelled out a quarter of an hour later as George Thomas beat the offside trap and chipped past Nik Tzanev.
The hosts suffered a blow before half-time as Dion Kelly-Evans saw red after picking up his second booking and Brentford took advantage of their man advantage to retake the lead four minutes after the break through Danny Parish.
The Bees man advantage was ceded just before the hour as Chris Mepham saw red for a second yellow card and five minutes later Coventry secured their draw as Maddison curled home a low free-kick from 20 yards.
Brentford made three changes from the draw with Birmingham City last time out as Tzanev replaced Jordan Carey in goal with Under-16s Parish and George Harmes replacing Kyjuon Marsh-Brown and Bradley Clayton.
Coventry had beaten The Bees 5-2 last season but a repeat of that scoreline looked unlikely as Brentford settled well into the opening stages of the game.
The pitch had been heavily watered before kick-off making it difficult for either side to find their passing range in first ten minutes or so.
With a slick surface and slippery ball it was no surprise that a mistake lead to the opening goal of the game.
There looked little danger as Kyle Barnett headed a long ball back to Jake Richards but The Sky Blues keeper fumbled the ball allowing Bohui to pick it up, steady himself and then curl it over the covering defenders from the edge of the box.
The slick pitch also made timing tackles difficult and Kelly-Evans was lucky not to see a straight red for a wild lunge on Parish, the end result being a yellow card for the Coventry left wing-back.
Despite leading The Bees were finding it hard to retain possession as Coventry's 5-3-2 formation made space in the midfield almost non-existent.
Coventry's midfield five also allowed striker George Thomas to drop deeper and pick up possession between Brentford's defence and midfield.
When Thomas got on the ball Coventry started to look dangerous and his ball nearly set Kyle Spence free but Tzanev was out well to save at his feet.
Thomas's next contribution was rather more telling as he beat Brentford's offside trap and chipped a finish over Tzanev from 15 yards to level things.
Zain Westbrooke should have put The Bees back in front two minutes later after a great 50 yard run by Bohui but his shot was tame and easy for Richards.
Tzanev made a fine save to deny Devon Kelly-Evans, tipping his shot round the post at full-strength before the temperature of the game rose considerably.
A tussle for possession between Mepham and Spence ending with a bit of pushing and shoving which ended with both players entering the referee's notebook.
Dion Kelly-Evans curled a shot over and Thomas couldn't convert after a good team move by the hosts before the hosts lost a man on the stroke of half-time.
Kelly-Evans had already been booked and when he barged over George Harmes as he broke free the referee had no alternative, despite what Coventry's vocal bench thought, but to produce a second yellow card.
Brentford seized the man advantage almost instantly after half-time as Jeremiah Kamanzi slid Parish free and he kept his nerve to curl past Richards from 15 yards.
The goal only increased the home bench's frustration with the officials and every decision the New Zealand referee made was repeatedly questioned by the Coventry coaching staff.
However they had no cause to complain moments before the hour as the referee produced a second yellow card for Mepham after he went in strongly as Coventry looked to break.
The Bees had been very bright in the second-half with their man advantage and initially it looked like that would continue despite both sides being down to 10 men.
Jeremy Steele's side appeared to have adjusted well to the loss of Mepham but they were hit by a sucker-punch as Gradi Milenge brought down Maddison on the edge of the box and the midfielder stepped up to curl the equaliser home past Tzanev.
Despite losing their lead Brentford continued to move the ball quickly, with the extra space helping them, while Coventry looked content to play on the break.
From one such break Ben Stevenson was inches away from putting the home side in front as his shot glanced off the top of the bar.
Tzanev was then called upon to produce a vital save as Jordan Shipley raced clear after beating the offside trap and he was also on hand a minute later to deny Stevenson from the edge of the area.
Brentford finished the game the stronger and could have been awarded a penalty right at the death as Kamanzi looked to be barged over by Barnett.
Audrius Laucys nearly made himself the hero in the last minute as he ran 50 yards beating three defenders in the process but his fierce shot flashed over the bar from the edge of the box as both sides had to settle for the point.
: Jake Richards; Jacob Whitmore, Kyle Barnett, Cian Harries, Dion Kelly-Evans; James Maddison, Luke Bromley, Ben Stevenson, Devon Kelly-Evans; George Thomas (sub Jordan Shipley 70 mins), Kyle Spence (sub Callum Maycock 81 mins)
: Corey Addai, Jay Albini, Dan Smith
: Dion Kelly-Evans 19; Kyle Spence 29; Cian Harries 76
: Dion Kelly-Evans 45+1
: George Thomas 25;James Maddison 64
: Nik Tzanev; Chris Mepham, Gradi Milenge, Seth Owens (sub Audrius Laucys 46 mins), Tom Field; Jeremiah Kamanzi, Zain Westbrooke, Reece Cole, George Harmes (sub Kyjuon Marsh-Brown 67 mins); Joshua Bohui (sub Makhosini Khanye 75 mins), Danny Parish
: Jordan Carey, Tony Guppy
: Chris Mepham 29; Gradi Milenge 64
: Chris Mepham 59
: Joshua Bohui 10; Danny Parish 49