Manchester City's losing streak stretched to five games across all competitions as Tottenham stunned the Premier League champions with a 4-0 victory at the Etihad Stadium.
On his 28th birthday, James Maddison scored twice in the first 20 minutes as Ange Postecoglou's visitors caught out their hosts on the counterattack.
Maddison was found unmarked at the far post by Dejan Kulusevski for his opener, then exchanged passes with Son Heung-min and dinked a fine finish over Ederson for his second.
City continued to dominate possession but struggled to find a killer pass, and their hopes of a second-half fightback were dashed when Pedro Porro – who spent three years as a City player between 2019 and 2022 – capped another lightning break early in the second half.
Erling Haaland clipped the crossbar but that was as close as City came to making it competitive, with Brennan Johnson completing the rout following fine work from Timo Werner, as the worst run of Pep Guardiola's managerial career continued.
Second-placed City could now find themselves eight points adrift of the summit after Liverpool’s trip to Southampton on Sunday.
Tottenham, meanwhile, climbed to sixth in the table, four points behind City.
Data Debrief: Uncharted territory for Pep
City have now lost five straight matches in all competitions, including two versus Tottenham after they were also beaten in the EFL Cup last month.
They are the first reigning top-flight English champions to lose five games in a row since Chelsea did so in March 1956.
This is the worst losing streak of Guardiola's glittering managerial career, with City last losing six in a row under Stuart Pearce in 2006.
Should their dismal run continue at Liverpool in eight days' time, their title defence may be in tatters before the festive season has even begun.