[UEFA CHAMPIONS LEAGUE] Rarely has a goalkeeper been so solely responsible for his team's loss in the Champions League. Arsenal understudy Lukasz Fabianski, pressed into service by the finger injury to Manuel Almunia, palmed a cross from Silvestre Varela into his own goal and was called for picking up a back pass from teammate Sol Campbell that immediately led to the winning goal by Radamel Falcao in Porto's 2-1 win over the Gunners Wednesday at the Estadio do Dragao. Despite the blunders, Fabianski got support from his coach.

"I believe that Fabianski is top, top level and has massive potential," said Arsenal boss Arsene Wenger. "It is not easy for a keeper to come in and out. What he misses at the moment is the number of games, but I have no doubt about his potential."

Wenger, in turn, said Swedish referee Martin Hansson -- he of the Thierry Henry handball controversy -- erred in calling a foul on Fabianski for picking up the backpass.

"I believe it [the back pass] was accidental," the Arsenal manager said. "Sol touched it accidentally. And the referee should give us time to build the wall."

After the foul was called, Porto took a quick kick. Ruben Micael put the ball down and tapped it to Falcao, who struck it into the empty net just as Fabianski turned from having his back to the ball and arguing with the assistant referee.

In between, Campbell scored -- giving his goals in successive Champions League matches for Arsenal. The previous one came in the 2006 Champions League final against Barcelona.

"I believe that Fabianski is top, top level and has massive potential," said Wenger. "It is not easy for a keeper to come in and out. What he misses at the moment is the number of games, but I have no doubt about his potential."

Porto-Arsenal Highlights: