Samuel Eto'o struck a hat-trick as Champions League holders Inter thrashed Werder Bremen 4-0 at the San Siro.
The Cameroon striker scored twice inside the opening half hour before Wesley Sneijder's strike after 34 minutes put Rafael Benitez's side out of sight.
Eto'o completed his treble nine minutes from the end to lift Inter to the top of Group A alongside Tottenham, who were also amongst the goals as they swept FC Twente aside 4-1.
Rafael van der Vaart saw a first-half penalty saved but the midfielder fired the north London club ahead two minutes after the break.
Spurs doubled their lead when Roman Pavlyuchenko scored a penalty but a hectic start to the second period also saw Nacer Chadli pull a goal back before Van der Vaart was dismissed.
The home side added two more goals, however, with Pavlyuchenko scoring his side's third penalty before Gareth Bale netted late on.
David Villa's second-half penalty ensured Barcelona avoided defeat away to Rubin Kazan.
The Russian champions beat Barca at the Nou Camp last year and went ahead when Cristian Noboa scored a 30th-minute penalty. Villa spared Barca's blushed with his spot kick on the hour, although Rubin almost snatch a late winner when Obafemi Martins hit the post.
FC Copenhagen are the surprise leaders of Group D after they secured back-to-back wins with a 2-0 success at 10-man Panathinaikos.
Dame N'Doye and Martin Vingaard struck first-half goals before Pana, beaten 5-1 by Barca in their opener, had Brazilian veteran Gilberto Silva sent off in the 52nd minute.
Summer signing Javier Hernandez scored the only goal of the game after 85 minutes as Manchester United won 1-0 at Spanish high-fliers Valencia, while Rangers won by the same margin at home to Turkish champions Bursaspor.
Steven Naismith scored Rangers' winner after 18 minutes.
Lyon moved clear at the top of Group B with a 3-1 win at Hapoel Tel Aviv.
Michel Bastos struck twice in the first half and while Hapoel goalkeeper Vincent Enyeama pulled a goal back from the penalty spot, Miralem Pjanic netted a third in injury time.
Schalke claimed their first home win of the season as they scored twice in the last 17 minutes to beat Benfica 2-0.
Jefferson Farfan opened the scoring before new signing Klass-Jan Huntelaar scored for the third game running, five minutes from the full-time.