Argentina winger Lionel Messi led Barcelona to a 3-0 home victory over French champions Olympique Lyon in their Champions League Group E opener on Wednesday.
The 2006 winners have only managed to score once from open play in their first three Primera Liga games this season and needed a slice of luck to take the lead against Lyon.
Messi crossed low into the area after 21 minutes and Lyon defender Francois Clerc diverted the ball into his own net.
Wednesday night's results
Arsenal 3 Sevilla 0
Man Utd 1 Sporting CP 0
Rangers 2 VfB Stuttgart 1
AS Roma 2 Dynamo Kiev 0
Barcelona 3 Lyon 0
Fenerbahçe 1 Inter Milan 0
PSV 2 CSKA 1
S Prague 2 S Bucharest 1
Frank Rijkaard's side struggled to add to the score until Messi scored a second in the 82nd.
Thierry Henry scored his first goal for Barca at the very end.
Arsenal too good for Sevilla
Arsenal gave Sevilla a lesson in what the Champions League is all about when they beat the UEFA Cup holders 3-0 in their opening Group H match.
Arsenal dominated almost from the first kick and sealed it with goals from Cesc Fabregas after 27 minutes and Robin van Persie in the 59th before substitute Eduardo da Silva slid home the third in stoppage time just minutes after coming on.
It was Sevilla's first match at this level since they played in the old European Cup some 50 years ago and despite playing their usual high tempo game, they rarely troubled the home side.
Fabregas's long-range strike appeared to be going wide until it took an emphatic deflection off Julien Escude and went in, while Van Persie scored from close range after Bacary Sagna flicked on a Fabregas free kick.
Ronaldo header seal victory for Man Utd
Cristiano Ronaldo headed Manchester United to a 1-0 win against his former club Sporting in their opening Champions League Group F match.
Closely marked in the first half, the Portuguese international winger managed to outsmart his former team mates in the 62nd minute to score with a diving header off a Wes Brown cross from the right.
Sporting narrowly missed an equaliser in the 78th minute when defender Tonel headed wide after Miguel Veloso's shot from outside the area was parried by Manchester keeper Edwin Van der Sar.
Goals from Simone Perrotta and Francesco Totti handed Serie A leaders AS Roma a confident start to their Champions League campaign with a 2-0 win over Group F rivals Dynamo Kiev on Wednesday.
Totti helps Roma to 2-0 win over Dynamo
Italy midfielder Perrotta sneaked in behind the Dynamo defence to head in a Max Tonetto cross and put the home side in front in the ninth minute.
Totti broke free from some tight marking 25 minutes into the second half to double the advantage with a diagonal right-footed shot.
Roma's 100th victory in European competition maintains their 100 per cent record, after they won their first three Serie A games and beat Inter Milan in the Italian Super Cup last month.
Slavia Prague beat Steaua in Champions League debut
Goals from Zdenek Senkerik and Tijani Belaid gave Slavia Prague a 2-1 victory over Steaua Bucharest in their Group H Champions League debut.
Senkerik put the home side ahead after 13 minutes when forward Stanislav Vlcek's close-range shot was deflected to him by goalkeeper Robinson Zapata. The Romanians hit back in the 33rd when defender Dorin Goian headed in a corner kick but Belaid put Slavia ahead again in the 63rd with a shot from inside the box.
The Prague side were making their first Champions League appearance.