. Elsewhere, Real Madrid recorded another big victory as they faced Copenhagen, while Juventus were held at home to Galatasaray and Paris Saint-Germain won big against Benfica.
• Brewin: Three things - City v Bayern
Manchester City slumped to a 3-1 home defeat as Bayern Munich put on a masterclass to maintain their perfect start to the defence of their European crown.
Franck Ribery gave Bayern the lead after six minutes when his powerful shot beat Joe Hart at his near post, with the City goalkeeper getting a strong hand onto the effort but being unable to prevent the ball from hitting the back of the net.
Thomas Muller then doubled the lead for Bayern ten minutes into the second half as Hart was exposed at the back, with Gael Clichy suffering a lapse in concentration to leave the Germany international unmarked.
Arjen Robben added a third four minutes later as Hart was once again beaten at his near post. Alvaro Negredo came off the bench to net a consolation for City, spinning his marker and curling his effort beyond Manuel Neuer in the 79th minute.
Jerome Boateng was given a straight red card for bringing down Yaya Toure after denying the City man a clear goal-scoring opportunity, but from the resulting free-kick David Silva struck the crossbar.
David Moyes came within 15 minutes of a morale-boosting victory, but Manchester United were pegged back for a 1-1 draw against Shakhtar Donetsk in their Champions League Group A encounter in Ukraine.
Danny Welbeck had struck in the first half to put United ahead, but Taison equalised in the 75th minute to ensure honours were even. There was even a late scare for United as Taison's cross deflected off Chris Smalling, forcing David de Gea into a fine stop.
The match also saw Ryan Giggs become the all-time record holder for appearances in the competition when he came on as a substitute midway through the second half.
Cristiano Ronaldo and Angel Di Maria each scored twice in an impressive 4-0...