Robin van Persie bagged a brace for Manchester United as they came from behind to defeat CFR Cluj, while European champions Chelsea scored three times late on to defeat Nordsjaelland 4-0.
Celtic enjoyed a memorable success on their travels against 10-man Spartak Moscow courtesy of Georgios Samaras' late header, while BATE Borisov provided the shock of the night by defeating Bayern Munich.
Manchester United were indebted to two goals from summer signing Van Persie as they were forced to come from behind to defeat Romanian outfit CFR Cluj in their Group H clash.
Cluj took a shock lead in the 14th minute as Pantelis Kapetanos turned home Modou Sougou's cross following some weak defending by the Red Devils, with Sir Alex Ferguson fuming on the touchline.
But they were back on terms in slightly fortuitous circumstances before the break as Wayne Rooney's free-kick looped home via the shoulder of former Arsenal striker Van Persie.
The duo combined again early in the second period with a goal of sheer class, as the England forward's delightful ball found his team-mate in the box, with the Dutchman producing a first-time finish with the outside of his left boot.
European champions Chelsea overcame Danish minnows Nordsjaelland in Group E, but were flattered somewhat by the final score in their 4-0 victory in Copenhagen.
Juan Mata scored the opening goal of the game shortly after the half-hour mark, slotting home first time from the right side of the penalty area after good work from Fernando Torres and Frank Lampard.
Nordsjaelland were inches away from levelling in the second period when Petr Cech produced an excellent finger-tip save to keep out Joshua John's curling effort before David Luiz settled Blues nerves with a superb free-kick (79) and then Mata struck again with another neat finish (82).
Roberto Di Matteo's men arguably saved their best for last when a slick move involving Torres and Oscar ended with Ramires tapping in from virtually on the goal line.
Greek striker Samaras' last-gasp header gave Celtic a dramatic 3-2 victory over 10-man Spartak Moscow in the Luzhniki Stadium to secure their first away win in the group stages of the Champions League.
Celtic striker Gary Hooper gave the visitors the lead in the 12th minute before Emmanuel Emenike netted twice from close range for the Russian club either side of the break.
Spartak defender Juan Insaurralde was sent off just after the hour mark for preventing Hooper going clean through on goal and Celtic levelled in the 72nd minute after a drive from substitute James Forrest deflected in off Spartak captain Dmitri Kombarov.
And to cap a remarkable night for the visitors, Samaras climbed highest in the box to head home an Emilio Izaguirre cross as the clock ticked beyond the 90-minute mark.
Next up for the Scottish champions is the small matter of back-to-back games against Barcelona, with the Lionel Messi-inspired Spanish side triumphing 2-0 away to Benfica thanks to goals in either half from Alexis Sanchez and Cesc Fabregas.
There were concerns for Barca, though, with Carles Puyol carried off with what looked like a very nasty arm injury, while Sergio Busquets is facing a suspension following his dismissal late on.
Chelsea face Shakhtar Donetsk in their next encounter, with the in-form Ukraine outfit drawing 1-1 away to Juventus on matchday 2, as Alex Teixeira's first-half opener was swiftly cancelled out by Leonardo Bonucci.
Manchester United's upcoming opponents in Group H are Braga, who warmed up for their trip to Old Trafford with a 2-0 success away to Galatasaray, with Ruben Micael opening the scoring before the interval and Alan adding a second deep into added time.
The shock result of the night came in Group F, where Bayern Munich were beaten 3-1 away by BATE Borisov, with the Belarus outfit now top of their section with a 100 per cent record after goals from Alexander Pavlov, Vitali Rodionov and Renan Bressan.
Valencia cruised to a 2-0 victory at home to Lille thanks to a brace from Brazilian striker Jonas, while the French outfit's evening was soured further by a red card for Mathieu Debuchy in the closing stages.