LONDON (REUTERS) - Lionel Messi proved a thorn in Arsenal's side yet again as his late second-half goals, including a penalty, gave Barcelona a 2-0 win at The Emirates in the first leg of their Champions League last 16 tie on Tuesday.
The Spanish holders' feared attack had been well shackled by a disciplined home side for much of the evening, but a lightning break after 71 minutes saw Argentine Messi teed up by Neymar to score past keeper Petr Cech for the first time in his career.
Messi, who netted four goals against the Gunners in 2010 and a double a year later in knockout round wins, doubled Barca's lead seven minutes from time when he beat Cech with a penalty, having been tripped by Arsenal substitute Mathieu Flamini.
Arsenal relied on counter-attacks and had chances, most notably from Alex Oxlade-Chamberlain and Olivier Giroud, but now have a daunting task to turn the tie around in the Nou Camp.
Barca's frontline of Luis Suarez, Messi and Neymar had scored 91 goals in all competitions this season but for the first 20 minutes they were subdued in an electric atmosphere.
Arsenal should have taken the lead midway through the first half when Hector Bellerin's scuffed shot fell for Alex Oxlade-Chamberlain in front of goal but he scooped his effort straight at goalkeeper Marc-Andre ter Stegen.
The Catalans began to move through the gears though and either side of halftime wasted two glorious chances.
Suarez headed Dani Alves's dinked cross wide when he should have scored at the end of the opening period and Neymar was denied by Cech after being played in by Andres Iniesta.
Starved of the ball for long periods, Arsenal still posed a threat though and Ter Stegen did well to keep out Olivier Giroud's close-range header from a Mesut Ozil cross.
Arsenal grew in belief but it cost them dear as they committed players forward and got stung.
With 19 minutes left Suarez and Neymar combined in devastating fashion and the Brazilian set up Messi who steadied himself and picked his spot to beat Cech.
Suarez then hit the post when he should have scored before Messi struck again, this time with a calmly struck penalty.
