Brentford emerged victorious in a Premier League match against Chelsea on Wednesday, with a final score of 2-0 to raise sack pressure on Frank Lampard.
An own goal by Blues' captain Cesar Azpilicueta and a second-half strike by Bryan Mbeumo secured the win for the Bees.
The loss marks Chelsea's fifth defeat in five games in all competitions under interim coach Lampard.
The defeat left Chelsea in 11th place in the Premier League table, with a disappointing performance this season despite their new US owners' large investments in players.
Chelsea's goal drought continued, with the team only managing to score once in seven games in all competitions.
Lampard tried to turn things around in the second half by bringing on winger Mykhailo Mudryk and striker Pierre-Emerick Aubameyang, but it was substituted Mbeumo who sealed the win for Brentford with a fiercely hit shot deflected beyond Chelsea's Kepa Arrizabalaga in the 78th minute.
With this defeat, media reports suggest that Chelsea is close to hiring former Tottenham Hotspur manager Mauricio Pochettino as coach from next season.
Meanwhile, Brentford moved up a spot to ninth in the league, eight points ahead of their West London rivals.