Ivan Toney bounced back from missing out on the England World Cup squad by scoring twice as Brentford stunned Manchester City to win 2-1 at the Etihad on Saturday.
A first home defeat since February leaves City two points behind Arsenal, who travel to Wolves later, at the top of the Premier League.
Toney, left out of England's squad for Qatar, made the most of a bright start by Brentford, breaking the deadlock in the 16th minute when Ben Mee headed back across the box and Toney sent a looping header over Ederson and into the net.
City had a strong shout for a penalty turned down for a handball before they equalised on the stroke of halftime when Kevin De Bruyne's corner was flicked on and Phil Foden drilled home a superb half-volley for his eighth league goal of the season.
There was a lengthy stoppage just after the break when Aymeric Laporte, who has been named in Spain's World Cup squad, received treatment after an inadvertent elbow from Ethan Pinnock opened a gash on his forehead.
City racked up 29 goalscoring opportunities but only managed six on target as Brentford's defence suffocated their attack and restricted striker Erling Haaland to a couple of half-chances.
That set the stage for Toney's winner as Brentford broke forward deep into second-half stoppage time, and the 26-year-old made no mistake as he fired home to secure a stunning victory.
"Obviously (being left out of the England squad was) a disappointment but I know I'm capable of and I won't let it put me down, I'll just keep going and keep doing well for Brentford," Toney told BT Sport.
"The motivation is the boys in the dressing room, and the fans as you can see. When we work hard, this is what we can do."
City stayed second in the table on 32 points, two behind leaders Arsenal who play Wolverhampton Wanderers later on Saturday. Brentford are 10th on 19 points.
