Nottingham Forest condemned Manchester City to a third straight Premier League loss as Enzo Maresca's side slipped further behind leaders Arsenal.
Despite starting the day in the Premier League's relegation zone, Forest triumphed 3-1 at the City Ground thanks to two goals from former City striker Liam Delap.
It is the first time in two years that City have lost three straight in the league and the first time they have conceded three goals to a team that begun the day in the Premier League's bottom three since September 2019.
City, who won seven straight games to start the season, remain in second place but are now six points behind leaders and title holders Arsenal.
The victory took Forest out of the relegation zone and sent Manchester United into the bottom three.
It could be a coming of age for both Delap and Forest, who had struggled to adapt to life under new boss Oliver Glasner, with just one win from their opening nine games.
Delap had scored once in his opening eight games following his club-record move from Chelsea, but his brilliant double suggested he can be the man to fire Forest to better things this season.
Delap began his career at City, but played just two Premier League games for the club.
City found themselves 2-0 down inside 20 minutes and trailed at halftime in a third consecutive Premier League game for the fist time since 2007, before the cub was taken over by Abu Dhabi United Group.
Jair Cunha scored Forest's opening goal, while City briefly threatened a comeback when Rayan Cherki scored early in the second half.
City's slump in form comes amid the backdrop of the ongoing appeal against Premier League charges, their season is showing signs of falling apart.