Joe Ledley needed just 16 minutes to make his mark in a Derby County shirt but Ollie Watkins earned Brentford a much-needed and deserved point at the death.Released by Crystal Palace when his contract expired at the end of last season, Ledley took plenty of time to weigh up his next career move amid offers from Turkey and China.Deadline day came and went without the Welshman finding a club but eventually Derby signed the midfielder as a free agent last Wednesday.And what an impression he made on debut here.When Sam Winnall cushioned a left-side cross in his direction, Ledley guided home a header from eight yards for his first goal in a year.But it wasn't sufficient to earn Derby all three points as Brentford finally made their 80 per cent of possession pay with just five minutes left on the clock.Watkins had been one of their more lively players and he slid in to poke home Florian Jozefzoon's ball in from the left in the nick of time and assuage a frustrated home crowd just as it looked as though Derby's resistance would hold firm.It was an opening half of scant chances despite plenty of endeavour and Brentford trailing at the break despite having the better of the game.There was a real edge to proceedings as well, with referee Andy Davies producing seven yellow cards in the opening 45 for an assortment of meaty challenges and one fully-blown melee.Neither team came into this one in sparkling form, both languishing in the lower reaches of the table with pre-season expectations set far, far higher.Derby, in their luminous green away kit on a misty night, started the brighter with Tom Lawrence's well-struck shot swerving in the air and forcing Brentford keeper Daniel Bentley to punch away.They led on 16 minutes from a well-executed move rounded off by Ledley, who has already become a favourite with the fans, who sung his name when he was taken off late on.Brentford responded energetically but tempers flared when Andre Wisdom went in hard on Romaine Swayers close to the touchline.Players from both teams flocked over to exchange handbags, with Wisdom pushing Ryan Woods in the back and Woods raising his hand in retaliation.Davies showed yellow cards to Wisdom, Woods and Bradley Johnson, managing to calm the situation and simmer down the crowd just a few yards away from the melee.Brentford continued to attack, with Watkins especially lively down the left.One of his crosses flashed right across the six-yard box untouched and, having switched flanks, another effort was deflected wide in stoppage time.Derby keeper Scott Carson also did well to react to an Andreas Bjelland header from a corner, turning it round the post, but Brentford couldn't find a leveller before the break.Brentford worked through the gears again after half-time, with Derby increasingly content to defend.There were occasional chances, with Neal Maupay heading over from Rico Henry's cross and Chris Mepham flinging himself at a corner but steering it wide.Nico Yennaris let fly from 30 yards and had Carson briefly worried, but his shot skipped comfortably wide of the post.But Watkins made no mistake and Brentford might even have snatched it, with Yoann Barbet curling a long-range free-kick just wide.