Miralem Pjanic scored one and set up another as Juventus beat Dinamo Zagreb 4-0 in the Champions League, while Monaco drew with Bayer Leverkusen.
Juventus needed an unfortunate own goal from Edoardo Goldaniga to squeeze past Palermo while Napoli beat Chievo.
Juventus, who beat Cagliari 4-0, move to the top of Serie A after Napoli were held to a 0-0 draw at Genoa.
Mauro Icardi inspired a superb comeback win for Inter as they beat Juventus 2-1 on Sunday, while Roma lost at Fiorentina.
Borussia Dortmund hit six, while Juventus were held by Sevilla on the second night of Champions League group stage action.
Zlatan Ibrahimovic's goal-scoring start to life at Manchester United shows he is up there with the world's best, Gianluca Zambrotta says.