Manchester – Manchester City conceded ground to leaders Liverpool atop the Premier League on Saturday after a stunning Andros Townsend goal contributed to a jaw-dropping 3-2 victory for Crystal Palace at the Etihad.
The defeat ended City's perfect home form in the league this season and arrived 28 years to the day since Palace last won on the road against the Blues.
City had not lost any of their previous 52 league games against teams outside the traditional "big six", a run dating back nearly two years to a defeat at Everton in January 2017.
But after Ilkay Gundogan had handed them the perfect start, City were undone by goals from Jeffrey Schlupp, Townsend and a Luka Milivojevic penalty – all three coming in an 18-minute spell.
Palace, trailing to Gundogan's well-placed headed opener, turned the game on its head with two goals in as many minutes just after the half hour.
First, City were badly exposed in midfield, failing to deal with Wilfried Zaha and Townsend, who played in James McArthur.
John Stones finally made a tackle but succeeded only in pushing the ball on to Schlupp, who capitalised on some uncertain defending from Kyle Walker, driving the ball past the defender and the diving goalkeeper Ederson into the far corner.
The Etihad crowd, who had been expecting another effortless victory after taking the lead, were stunned into silence and the situation was about to worsen.
A free-kick was headed out by Aymeric Laporte, Gundogan missed a chance to clear his area and Bernardo Silva succeeded only in heading the ball out to Townsend.
The England international connected with an incredibly well-executed, first-time left-foot volley that soared above the diving Ederson and into the top of the City net from fully 30 yards.
It was a stunning development for a City side that have lost just two home league games – to Chelsea and Manchester United – in the two-and-a-half seasons in which Guardiola has been in charge.
There had been little sign of such drama as City took their customary stranglehold on the game, enjoying 78 percent of the possession in the first half.
They took a predictable lead in the 27th minute with an excellently worked goal, Leroy Sane passing the ball back to Fabian Delph on the left wing.
His accurate cross allowed Gundogan to ghost between defenders Mamadou Sakho and Patrick van Aanholt to head a superb finish past Vicente Guaita.
But, with Sergio Aguero and Kevin De Bruyne watching from the bench and David Silva and Fernandinho absent from the squad completely, there were surprisingly few moments of real danger from the defending champions.
Guardiola had seen enough four minutes into the second half, bringing on Aguero but not even the clubs all-time leading goalscorer could bring about an immediate improvement, with City conceding a third in the 51st minute.
Aaron Wan-Bissaka's cross found the head of Townsend, whose effort struck the right-hand post, rebounding into play for Max Meyer and forcing a panicked Walker into making a challenge referee Andre Marriner judged to be a foul.
Milivojevic showed admirable composure to stride up and send Ederson the wrong way from the resulting penalty.
Guardiola brought De Bruyne off the bench in an effort to spark some life into his side's performance and it worked, with a 25-yard Gundogan volley flying just wide and Sane hitting the outside of the post with a terrific 30-yard free-kick.
De Bruyne himself guaranteed a frantic final five minutes as his deep right-wing cross, intended for Sane at the far post was misjudged by Guaita and flew into the top corner for the last goal of the day.