Cesc Fabregas and Carlos Vela each scored twice as Arsenal kicked off their latest Champions League campaign in emphatic fashion with a 6-0 hammering of Braga at the Emirates.
Fabregas' ninth-minute penalty set the tone of a thoroughly one-sided affair on a big night for English clubs, with the Gunners' Premier League rivals Chelsea also routing Zilina in Slovakia.
Andrei Arshavin and Jack Wilshere put Arsene Wenger's men out of sight by half-time and after Fabregas' second it was left to the man who replaced him, Vela, to round off the victory.
The other game in Group H saw Shakhtar Donetsk beat Partizan Belgrade 1-0 thanks to a goal from Darijo Srna.
Chelsea enjoyed a resounding success against MSK Zilina in Slovakia with Nicolas Anelka's double steering Carlo Ancelotti's men home to a 4-1 win.
Michael Essien had opened the scoring after 13 minutes and Daniel Sturridge swept home the Blues' fourth after a slide rule pass from Yossi Benayoun to complete a comfortable night for the Premier League champions.
Spartak Moscow joined Chelsea on three points at the top of Group F with Cesar Azpilicueta's late own goal enough for a 1-0 win over Marseille.
Jose Mourinho's Real Madrid eased to a 2-0 win over Ajax at the Bernabeu but they should have won far more comfortably than they did.
Vurnon Anita's own goal put Real 1-0 up at half time and Argentina striker Gonzalo Higuain doubled their advantage after turning home Mesut Ozil's cross in the second half. Higuain missed a great chance to hit a second when played through by Cristiano Ronaldo, and the Portuguese forward missed several opportunities of his own.
Also in Group G, seven-time winners AC Milan were pushed by French underdogs Auxerre before recent signing Zlatan Ibrahimovic showed his worth with a pair of goals to secure a 2-0 win for the Italians.
Bayern Munich left it late to see off Roma 2-0 in Group E, with Thomas Muller's brilliant 78th-minute volley breaking the deadlock for the Germans and then a close-range effort from Miroslav Klose sealing the points.
In the group's other game Romanians CFR Cluj got off to a winning start, with Ionut Rada and Lacina Traore scoring early in a 2-1 win over Swiss side Basel, for whom Valentin Stocker's 44th-minute header was not enough.