Contrasting Champions League nights for Arsenal and Chelsea

Only one English side is guaranteed a place in the knockout phase of the Champions League after Robin Van Persie fired Arsenal through with one game to spare last night while Chelsea's future in the European football's premier competiting is in serious doubt.

Van Persie headed home an Alex Song cross just after half time before adding a second four minutes from time from a Thomas Vermaelen flick-on to ensure the Gunners sealed qualification as champions of Group F with one game to spare with victory over Borussia Dortmund. But Chelsea stumbled against German opposition, losing 2-1 to Bayer Leverkusen in Group E, leaving Andre Villas-Boas' side needing to beat Valencia or keep a clean sheet to avoid dropping into the Europa League.

Manchester City and Manchester are not guaranteed to qualify either after they suffered defeat to Napoli and a draw with Benfica respectively.

"It's in our hands to qualify," Villas Boas, the Chelsea, manager, said. "It's a game at Stamford Bridge and we expect to do our job. That's our responsibility and we don't want to let the fans down. The most important thing for us at the moment is to qualify and eventually see what happens. That's our main focus."

His opposite mumber at Arsenal, Arsene Wenger, was once again left marvelling at the performance of Van Persie who has now scored 17 goals this season and has racked up 33 goals in 30 games for the calendar year.

"He is in a period where he doesn't have to look for goals," Wenger said. "They just come naturally for him, he is always in the right place at the right moment. He got two goals tonight from positions where it looks easy but that's only because he understands the game so well. At the moment Robin is an exceptional player. He takes advantage of our offensive style. At the moment he is the one who scores all the goals so we hope we can keep him fit and with us for a long time."

Dortmund manager Jurgen Klopp described the 28-year-old's display as "simply unbelievable".

Villas-Boas, meanwhile, admitted confidence was low in the dressing room.

"Yes, but that's when they expect the manager to inspire them," he said. "That's my job. That's my task, to inspire these people and motivate these people to change our faith."