Vitaly Janelt scored two classic goals and Christian Eriksen opened his Brentford account in a heartbreaking derby in the 4-1 win over Chelsea at Stanford Bridge.
Bees was a better side in the first half, but Chelsea took the lead through a cross from Antonio Rudiger.
The great Brentford responded three times in the space of 10 minutes, and after a fierce counterattack, Janelt responded with two bright blows on either side of Eriksen's medical end.
Yoane Wissa scored the only goal of the game against Bees in their first win over Chelsea since 1939, ending a six-goal win over London rivals to move 11 points clear of the Premier League relegation zone.
Edouard Mendy was sent off in the space of five minutes for a foul, and Ivan Tone escaped a cross from the crossbar by a stranded Chelsea keeper.
Toney fired in a powerful shot from Mendy, and the extravagant striker headed in close range from a Brentford impressive start.
Chelsea were short of ideas, but Harkenziech called for David Raya to be kicked out with a left-footed shot after being sent off the Mason Mount in the penalty area.
Rudi Garcချa missed the opening goal of the second half in the third minute of the second half when a powerful right-footed shot from almost 40 yards out overtook Raya.
Two minutes later, digging into Brentford with his left foot, Janelt was able to do well and Chelsea's happiness was short-lived.
Four minutes after Bryan Mbeumo was spotted running into the box, The Bees pulled one back and Bez took the lead over Chelsea.
Thomas Frank's team continued to pound the ball and award it with a brilliant third in less than an hour, and Tony overtook Mandy and gave the back of the net a superb free-kick into the back of the net. From the net with the left foot.
Wenger has been linked with a move away from Stamford Bridge this summer.
what do you mean? Venomous Bees Blues European Champions
Brentford have produced one of their Premier League performances to ensure they remain top notch.
The Bees have not beaten Chelsea eight times since 1939 and could not have imagined stabbing their West London rivals in the backyard in this way.
Chelsea have won every game since Roman Abramovich sold the club, but they were significantly worse off before next week's Champions League quarter-final first leg against Real Madrid.
Janelt enjoys watching.
German midfielder Janel has scored just three goals this season, but has twice twice.
The 23-year-old's second goal came from a sweet finish, a constant threat from top-flight Brantford.
Incredible Eriksen does not stop.
Eriksen ran for Brentford, dreaming of returning to international duty with Denmark and scoring goals for the Netherlands and Serbia.
The midfield creator once again showed his class in the middle of the park after the clinic.
Key Opta Facts
The match was the biggest joint victory in the Premier League away from home with a new team from the start of the season (Leeds beat Aston Villa 3-0 in October 2020).
Brentford scored four or more goals in the top-flight London derby for the first time since a 5-2 win over Charlton in October 1937.
Chelsea lost 3-1 or more in the Premier League London derby at Stamford Bridge and another 3-0 defeat to Arsenal in April 1997.
Eriksen scored his first Premier League goal since December 2019, when he was targeting Tottenham Hotspur and Norwich. The midfielder was instrumental in eight goals (three assists and five assists) against Chelsea, all of which came to Stamford Bridge.
What is the next one?
Chelsea are set to reunite before Wednesday's La Liga clash with Real Madrid, while Brentford face another derby at home to West Ham next Sunday.