Thirteen days on from the ex-Celtic boss’ appointment and a week after victory at Birmingham in his maiden match, Neil Danns and substitutes Mark Davies and Craig Davies scored to ensure Lennon got off to a winning start at the Macron Stadium.
He will realise he still has plenty of work to do, especially after a first half where familiar failings were evident, and the three points earned were not enough to move Wanderers out of the bottom three.
But, even though Jon Toral’s strike denied them a clean sheet, Lennon has already had a positive effect after picking up six points from nine since replacing Dougie Freedman.
Lennon was paraded to the home faithful on the pitch prior to kick-off and the Northern Irishman had barely had chance to take his seat when Jermaine Beckford cut inside and fired a shot at David Button inside 20 seconds.
The Bees had an early opening themselves as Jota almost bent a curling effort beyond goalkeeper Andy Lonergan’s reach.
Lonergan was then well placed to hold on to Alex Pritchard’s rasping drive which went straight down the stopper’s throat.
For all the attacking intent Wanderers displayed, there was a clear lack of quality, epitomised by Beckford’s weak volley and Danns’ harmless efforts from distance.
The visitors were trying more inventive ways in their attempts to break the deadlock as a clever corner routine ended in Lonergan pushing Alan Judge’s volley wide, with Jake Bidwell nodding the resulting corner over in the final act of the first period.
Seven days ago a Matt Mills goal gave Lennon the dream start at Birmingham and the defender directed a similar headed chance just past the post at the start of the second half.
Danns again came close moments later after Beckford had found some joy down the left flank and steered the ball across for the winger, whose low effort was dealt with by Button.
It seemed as if Wanderers’ profligacy would continue to haunt them but that all changed in the 61st minute.
Danns drifted inside from his right-wing station and, after being afforded time and space, he drove a glorious left-foot try beyond Button’s dive and inside the near post.
It failed to open the floodgates, though, as the hosts somehow spurned a three-on-one opportunity with Darren Pratley and Beckford failing to get shots away.
Visiting manager Mark Warburton was then forced into a change as Alan McCormack was stretchered off with a serious-looking injury which triggered a lengthy delay.
It was the hosts who almost got caught out by that stoppage, Andre Gray nearly bringing a long ball under his spell inside the area.
However, substitute Mark Davies made an immediate impact to double the lead with 14 minutes remaining.
The central midfielder collected the ball inside the area, shimmied past his marker and stroked the ball beyond Button with a touch of class.
Yet Brentford would not lie down, with Lonergan tipping Jonathan Douglas’ header over before substitute Toral pulled one back.
The Spaniard controlled a deep, back-post cross into his path and lashed beyond Lonergan to give the Bees hope.
They poured forward during the seven minutes of stoppage time and were caught out with keeper Button up the pitch from a corner as Craig Davies collected Lonergan’s throw out and rolled into an empty net from 30 yards to seal a happy afternoon for Lennon.