They took the lead on 17 minutes, Watkins turning brilliantly on the edge of the box to fire in a low drive that keeper Kelle Roos could only parry into the path of Mbeumo who drilled home just inside the post.

The Bees stretched their advantage a minute later with a superb flowing counter attack that ended with Mbeumo crossing low for Watkins to sidefoot home.

The hosts made it three just before the break when a well-worked corner found Watkins whose close-range effort was blocked by his own defender Henrik Dalsgaard but fell kindly for him to squeeze the ball home through a sea of legs.

Brentford dominated possession for the first 45 and Derby were booed off at the break by the travelling fans who saw their side fail to muster a single effort on target.

Sergi Canos, playing in a deeper wing back role, was the Rams' chief tormentor and was at the heart of everything the Londoners created as they ran riot.

He forced Roos into a diving save just before the opening goal, but once the deadlock was broken, confidence coursed through Thomas Franks' side.

Roos had to be at his best on the half hour as Said Benrahma, making his first start of the season, fired in a blistering angled drive that he tipped wide of the far post at full stretch.

And the stopper had defender Krystian Bielik to thank for keeping the first-half scoreline down when he cleared Watkins' volley off the line.

Brentford could have been further ahead at the interval, another superb counter-attacking move that ended with wing back Rico Henry blazing over from the edge of the box with time on his side.

Brentford closed the game down after the break and did not take as many chances in the final third, but were still comfortably in control.

Canos screwed a shot just wide of the far post after good work from Mbeumo.

Derby's only worthwhile effort came on 53 minutes when Tom Lawrence showed intent with a surging run but drilled his 20-yard effort inches past the left-hand post.

Mbeumo should have made it four for the Bees just before the hour when he latched onto a through ball, rounded the keeper but laid back for Watkins whose first time drive was blocked by a desperate Richard Keogh lunge.

Bees substitute Joel Valencia was inches away from marking his home league start with a goal as he slid in, but narrowly missed Canos' cross at the far post.

Watkins might have grabbed the hat-trick his all-action performance deserved at the death when he chased a superb through ball but keeper Roos was smartly off his line to save with his chest outside the box.