LONDON (AP):

Prizing Mesut Ozil away from Real Madrid seems like one of Arsene Wenger's canniest moves at Arsenal.

Just a month into his Arsenal career, özil's impact has been devastating, living up to the club-record transfer fee of €50 million (US$66 million).

After the assists came the first goal in an Arsenal shirt yesterday, a stylish finish before setting up Olivier Giroud as the London club coasted to a 2-0 victory over Napoli in Champions League Group F.

On the day Wenger marked 17 years in charge at Arsenal, belief is growing at the club that a first trophy since the 2005 FA Cup could be possible, although there's a long way to go until May.

Arsenal are top of the Premier League, and now three points clear of both Napoli and last season's Champions League runners-up Borussia Dortmund at the top of one of the toughest groups.

özil took just eight minutes to put Arsenal in front at the Emirates Stadium against Serie A's second-place club.

"His skill, his finishing, it is everything that you dream to see when you sit in the stands watching football," Wenger said. "It's always on your mind a little bit (scoring your first goal), so he got rid of it."

The Germany playmaker then turned provider to set up Giroud in the 15th minute.

This wasn't the return to London that Napoli coach Rafa Benitez desired, having been jeered by his own Chelsea fans last season during an unpopular interim reign.

The Spaniard rued the lack of concentration that led to Arsenal scoring the quick-fire goals.

"We lost the ball on several occasions and we paid for those mistakes against a team with a lot of quality," Benitez said through a translator.

"We know we have quality, but we must show it from the start of the game."

Borussia Dortmund and Chelsea recovered from poor starts in the Champions League by winning their first group matches, while Barcelona beat 10-man Celtic 1-0 to avoid a second consecutive loss at Celtic Park.

Robert Lewandowski scored a brace as Dortmund, last-season's runner-up, defeated Marseille 3-0 in Group F. Arsenal lead the group with six points after a 2-0 win over Napoli.

Chelsea kick-started their campaign with a 4-0 rout of Steaua Bucharest in a Group E dominated by Schalke.

Missing the injured Lionel Messi, Barcelona earned a workmanlike second win in Group H, courtesy of Cesc Fabregas' strike at the scene of last season's shock defeat.

Mario Balotelli converted a penalty in the fourth minute of injury time to give AC Milan a 1-1 draw against Ajax.