A deflected William Gallas opener and second-half own goal from Gary Caldwell put Arsenal FC firmly in the driving seat in this UEFA Champions League play-off tie as the visitors earned a 2-0 victory against Celtic FC.
The home team had more than matched Arsène Wenger's side for the best part of 45 minutes in Glasgow before Gallas deflected Cesc Fàbregas's free-kick into the net just before the interval. From then on there was only ever going to be one winner, however, and 19 minutes from time Celtic captain Caldwell inadvertently doubled the visitors' lead, diverting Gaël Clichy's cross into his own net.
Celtic manager Tony Mowbray had raised eyebrows by deploying Georgios Samaras as a lone striker at the expense of Scott McDonald and Marc-Antoine Fortuné, with Aiden McGeady providing support from the five-man midfield. The Irish international started brightly, and after Andrei Arshavin had had a goal ruled out for offside a lung-bursting run from McGeady created Celtic's first opening. The winger sent Scott Brown through on goal only for Thomas Vermaelen to save the day with a timely intervention.
Celtic looked the likelier scorers and Brown did test Manuel Almunia four minutes before half-time with a low drive from inside the box after a surging run from Andreas Hinkel. Yet moments later – in somewhat fortuitous circumstances – Arsenal were ahead. Artur Boruc looked to have Fàbregas's free-kick covered before the ball took a massive deflection off the back of Gallas and bounced off the upright and into the net. The onus was now on Celtic to chase the game, leaving themselves open to Arsenal's counterattacking threat and Denilson went close three minutes after the restart, the Brazilian curling a right-foot effort just wide. Robin van Persie tugged a shot past the same upright on 54 minutes as the visitors threatened to increase their lead.
Mowbray responded by sacrificing Massimo Donati and Samaras for McDonald and Fortuné, but it made little difference as the waves of attacks continued towards the home goal. Celtic did threaten, briefly, but having opened the scoring at one end, Gallas prevented a certain equaliser at the other midway through the second period when he cut out Fortuné's cross with McDonald waiting to pounce at the back post. It would prove the hosts' last chance and four minutes later their misery was compounded when Caldwell could only divert Clichy's cross from the left past a stranded Boruc, leaving Arsenal strongly placed to seal progress to the group stage next Wednesday in north London.