Manchester City looked far from potential Champions League winners as they fell to a surprise 2-1 loss at home to Olympique Lyonnais on Wednesday with a flat performance that leaves them with plenty of work to do to progress from Group F.
The Premier League champions, favourites with some bookmakers to win Europe's top club competition this season, were well below their best throughout and now face a serious challenge to progress from a group which also features Germany's Hoffenheim and Ukraine's Shakhtar Donetsk.
City manager Pep Guardiola, serving a suspension, was forced to watch the game from the stands as his assistant Mikel Arteta took charge and it was a frustrating night for the pair, whose side have now lost four games in a row in the Champions League.
In contrast to a flat-looking City, Bruno Genesio's Lyon delivered a tactically superb display, defending in numbers to nullify City's normally dangerous forward line and then counter-attacking at pace.
The visitors took the lead in the 26th minute through Maxwel Cornet, who drove home after Fabian Delph made a hash of clearing a Nabil Fekir cross from the left.
Gabriel Jesus, City's Brazilian striker, had a strong appeal for a penalty turned down but that was one of the few moments in which he really threatened in the box.
Ilkay Gundogan had an effort disallowed after Italian referee Daniele Orsato ruled that Raheem Sterling was offside but City's frustrations in attack were not their only problems.
Fekir, who was strongly linked with a move to City's Premier League rivals Liverpool in the close season, then made it 2-0 to the French side in the 43rd minute, bursting clear and beating Ederson with a low drive after Fernandinho had given up possession in midfield.
It could even have been 3-0 when Memphis Depay hit the post on the hour after a magnificent through ball from Tanguy Ndombele, but after that let-off City earned themselves a lifeline through Bernardo Silva, who produced a smart finish after a superb jinking run from substitute Leroy Sane.
City's attempts to get an equaliser, however, were foiled by a combination of a well-drilled Lyon defence, which kept chances to a minimum, goalkeeper Anthony Lopes, who produced a fine save to deny substitute Sergio Aguero and some poor decision-making from City's forwards.
The defeat was a fourth-straight Champions League disappointment for City, who lost both legs of last season's quarterfinal against Liverpool and the second leg of their last-16 clash against Basel.