A goal in each half saw Brentford win at Stamford Bridge for the second year running and ended a six-match winless Premier League run for Thomas Frank’s Bees.

Chelsea dominated possession but were undone by goals late in each half. The first came when Cesar Azpilicueta turned Zanka’s near-post flick-on into his own net eight minutes before the break.

After soaking up Chelsea pressure for much of the second period, Brentford scored a classy counter-attacking goal through substitute Bryan Mbeumo to wrap up the points late on.

For all their pressure, Chelsea weren’t able to find a way through the Bees’ well-drilled backline as they suffered a fifth-straight league defeat under Frank Lampard.

Both sides make four changes for west London derby

There was plenty of symmetry in the team news, with both sides making four changes from their last Premier League match and switching to a back five.

For Brentford, Mads Roerslev replaced Aaron Hickey at right wing-back with Zanka joining Ethan Pinnock and Ben Mee in the heart of defence.

Frank Onyeka came in for the injured Christian Norgaard in midfield while Yoane Wissa partnered Ivan Toney up front.

Kevin Schade and Mbeumo were the other two Aston Villa starters to drop to the bench.

Following defeat to Brighton and Hove Albion 11 days ago, Frank Lampard brought Cesar Azpilicueta in on the right side of defence, Trevor Chalobah moving inside to centre-back, with Thiago Silva, Ngolo Kante and Mateo Kovacic their other changes.

Silva partnered Chalobah and Wesley Fofana in defence while Kovacic and Kante joined British record signing Enzo in midfield.

Out went Christian Pulisic, Benoit Badiashile, Denis Zakaria and Mykhailo Mudryk.

Brentford: Raya; Roerslev, Zanka, Pinnock, Mee, Henry (Hickey 90+2); Janelt, Onyeka (Baptiste 62), Jensen (Damsgaard 62); Wissa (Mbeumo 62), Toney (Schade 82)

Subs not used: Cox, Hickey, Schade, Dasilva, Ghoddos, Stevens

Chelsea: Kepa; Azpilicueta (Mudryk 46), Fofana, Silva, Chalobah, Chilwell; Enzo (Felix 79), Kante, Kovacic; Gallagher (Aubameyang 46); Sterling (Madueke 79)

Subs not used: Mendy, Badiashile, Pulisic, Loftus-Cheek, Ziyech

Attendance: 39,929

Bees lead at the break after a first half of few chances

With the two sides matching each other up formation-wise, the opening 20 minutes were cagey at Stamford Bridge.

Brentford were happy to sit off Chelsea and soak up the pressure. For the home side’s part, Raheem Sterling and Conor Gallagher, playing as the main attacking threat, were isolated up against Brentford’s back three.

Their lack of service meant that when they went looking for the ball, Chelsea had no attacking players in the box, much to the frustration of the home fans.

It took more than 20 minutes for an effort on goal, Vitaly Janelt deflecting Kante’s long-range shot behind. Silva then tamely looped a header into David Raya’s clutches before the Bees had their first openings of the game.

Mee glanced a header off target from Mathias Jensen’s cross. Moments later cries for a penalty were waved away when Onyeka went down under pressure from Chalobah in the box.

Kante was proving to be Chelsea’s most effective attacking threat, popping up in and around the Brentford box. It was he who teed up Enzo for a rising shot which Raya tipped over. He then curled wide from the right-edge of the box, something Sterling did almost identically shortly after.

Brentford hadn’t had a shot on target in the opening 37 minutes and so it remained until half-time, even though they went in ahead. The goal came from a in-swinging Jensen corner which Zanka flicked on at the near post, the ball bounced off Azpilicueta’s arm and trickled over the line.

The extent to which Brentford had frustrated Chelsea was perhaps best summed up by Silva’s ambitious shot from 30 yards late in the half which dribbled wide.

Brentford survive the storm, with Mbeumo delivering the sucker punch

Having spent nearly £600 million on new players this season, Chelsea weren’t without options off the bench and Frank Lampard introduced two of this season’s arrivals, Pierre-Emerick Aubameyang and Mudryk, at half-time.

That double change, which also saw Chelsea go to a back four, gave them a much tighter grip on the game.

Brentford spent most of the opening exchanges of the second half penned on the edge of their own box, struggling to find any sort of out ball.

Kante drove a shot across goal and wide from 15 yards, Ben Chilwell had an effort blocked, and Raya dealt easily with Aubameyang’s low drive.

It seemed only a matter of time before Chelsea would level. Aubameyang beat Raya to a Sterling nod back and glanced onto the roof of the net. Silva met a Mudryk free-kick but flicked wide, Aubameyang brought another regulation save out of Raya, and Sterling had a shot blocked by Zanka.

However, just as Chelsea’s subs had changed the flow of the game, Brentford had options off the bench of their own.

A triple change just past the hour saw Mbeumo, Mikkel Damsgaard and Shandon Baptiste introduced and it was a different game after that.

Chelsea still dominated possession, but they carried nowhere near as much attacking threat. Baptiste and Damsgaard harried in midfield and Mbeumo gave Brentford more pace on the break.

The fresh legs also enabled Brentford to press higher up the pitch. Janelt’s persistence on the edge of the Chelsea area saw a loose ball drop to Mbeumo who fired over from a tight angle.

There were then more calls for a Brentford penalty as Toney fired a shot into the hand of Chilwell at close range, following a run and cross from Rico Henry.

The appeals had hardly died down before Brentford put the game to bed with a clinical counter attack. The move started with every player, bar Kepa, in the Brentford half, and ended with Mbeumo lashing home from eight yards, via a slight nick off Silva - in between, Mbeumo had carried Toney’s through ball 40 yards up the right flank before driving into the box to open up a shooting opportunity.

There were still 12 minutes on the clock when the goal went in, but a Chelsea comeback never looked on the cards. Indeed, the imperious Pinnock could have made it three from Janelt’s deep cross but his hooked effort floated over the bar.

When substitute Noni Madueke planted Chelsea’s final chance well off target in stoppage-time, those in blue knew the game was up as Brentford ended their six-game winless run in style.

Frank: It’s remarkable that we’ve won here again

Head coach Thomas Frank was delighted with his side's performance at Stamford Bridge.

Mbeumo: I knew I could be a threat

Bryan Mbuemo said that coming on during the second half at Stamford Bridge, with Brentford one goal up, provided him with ideal conditions to get on the scoresheet.