Manchester City slumped to a first defeat in 19 Premier League games as injury-hit Norwich deservedly won 3-2 at Carrow Road.
The champions had last lost in the league in January - a 2-1 reversal at Newcastle - but the Canaries were in inspired form to deny Pep Guardiola's side.
Norwich, who were without seven players and could not call on City loanee Patrick Roberts, took the lead in the 18th minute.
Kenny McLean headed home a corner at the near post and the Canaries were soon 2-0 up when Teemu Pukki teed up Todd Cantwell to tap into an empty net.
City, who are already five points behind leaders Liverpool with just five games played this term, got themselves back in the game before half-time when Sergio Aguero nodded home Bernardo Silva's cross.
Yet the visitors' disastrous day took another turn when Nicolas Otamendi lost possession 20 yards from his own goal, and Emiliano Buendia set up Pukki to add a third in the 51st minute.
City pressed a resolute Norwich defence for the remainder of the game, finding an 87th-minute consolation through Rodri, but the hosts held on for a famous victory.
- Norwich registered only their second win in their last 15 Premier League meetings with the reigning champions (W2 D1 L12) – their other win was also against Man City in May 2013.
- Manchester City suffered a Premier League defeat against a newly-promoted opponent for the first time since March 2015 against Burnley – they had been unbeaten in 25 such matches before today, including all 18 under Pep Guardiola.
- Norwich’s Teemu Pukki has been involved in eight goals (6 goals, 2 assists) in his first five Premier League appearances – only Sergio Agüero has been involved in more goals in a player’s first five appearances in the competition’s history (9).
- Man City striker Sergio Agüero became the third player to score in a team’s first five Premier League matches of a season, after José Antonio Reyes for Arsenal in 2004-05 and Wayne Rooney for Manchester United in 2011-12.
- Manchester City conceded three goals in a league match against a newly-promoted team for the first time since August 2013, when they lost 3-2 away at Cardiff City.
- Norwich’s Emiliano Buendía is the first midfielder to assist as many as four goals in his first five Premier League appearances since Eden Hazard in 2012.
- Manchester City conceded twice in the opening half-hour of a Premier League game for only the second time under Pep Guardiola, also doing so in December 2016 against Leicester City, when they conceded three times.
- Norwich striker Teemu Pukki is the first player to score in his first three home Premier League appearances since Alexandre Lacazette in 2017, and the first Finnish player to do so since Jonatan Johansson in 2000.
Odds correct at time stated