Real Madrid, even without the injured Gareth Bale, made it 10 goals in two Champions League games with an easy 4-0 win over FC Copenhagen at the Bernabeu.
Cristiano Ronaldo bagged the first two, with Angel Di Maria also weighing in with a double.
Roberto Mancini, in his first game as Galatasaray coach since departing Manchester City, will have been delighted with a 2-2 draw at Juventus, Umut Bulut grabbing an equaliser with two minutes to go.
Zlatan Ibrahimovic wasted little time in showing that Paris Saint Germain will be serious contenders in the Champions League this season by having a hand in all three goals as his side raced into a 3-0 lead against Benfica inside the first 30 minutes.
Ibrahimovic opened the scoring when he tapped in Gregory van der Wiel's cross in the fifth minute before setting up Marquinhos for the second with a clever flick.
A header from the Swede made the game safe as PSG coasted to a 3-0 win.
Still in Group C, Anderlecht's hopes already look over after they lost 3-0 at home to Olympiakos, Greece striker Kostas Mitroglou getting a hat-trick.
In Manchester City's group, CSKA Moscow picked up their first points of the campaign with an unconvincing 3-2 home win over Viktoria Plzen, the Czech side's goalkeeper Matus Kozacik gifting them the winner by letting in a back pass.
Bayer Leverkusen snatched a dramatic victory in Manchester United's group through midfielder Jens Hegeler's 90th-minute winner against Real Sociedad.
Simon Rolfes had given Leverkusen the lead in first-half injury time.
But former Arsenal striker Carlos Vela looked to have earned the Basque side a point with a 51st minute equaliser, bundling the ball home after Bayer keeper Bernd Leno saved his penalty.
However Hegeler, on as a substitute, struck with a curling free-kick for the Germans.