Beating an Arsenal offside trap in the 25th minute, Lionel Messi found a crease to connect with David Villa, who rewarded the pass with an easy flick past Wojciech Szczesny for the lone goal of the first half at the Emirates Stadium in the first leg of the Round of 16 Champions League match.
It was Villa's first Champions League goal since converting a penalty kick against FK Rubin Kazan on Sept. 29.
The Gunners survived a great Barcelona opportunity in the early going. Messi nearly scored in the 14th minute, but his running right-footed chip shot was just wide of the post.
In the 29th minute, Pedro was unable to flick in a relatively easy shot.
Arsenal have had their chances, as well. A Robin van Persie shot along the left side was shanked wide left -- an attempt that the Dutch star could certainly have done better with.
On an Arsenal counter-attack, Fabregas was unable to get his cross on target with Van Persie and Walcott pushing forward.
With midfielder Samir Nasri on the field, Arsenal have made an effort to attack, even before the Barcelona goal, but have come up short.
Nasri and Alex Song were each booked with a yellow card.
ARSENAL: Szczesny; Eboue, Djourou, Koscielny, Clichy; Song, Wilshere, Walcott, Fabregas, Nasri; Van Persie.
BARCELONA: Valdes; Daniel Alves, Pique, Abidal, Maxwell; Busquets; Xavi, Iniesta; Pedro, Villa, Messi.