A second-half equaliser from Antoine Griezmann gave Barcelona an important away goal and helped them draw the first leg of their UEFA Champions League Round of 16 match against Napoli at the San Paolo Stadium on Tuesday.

The Catalans dominated possession from the word go but failed to harm a well-maintained defence laid by the hosts. Surprisingly, it was Napoli who drew the first blood at the 30th-minute mark through Dries Mertens.

The Belgian, fed by Piotr Zielinski outside the box, curled the ball inside the Barca net to score his sixth European goal of the season. The strike, which was his 121st in Napoli colours, also made him the club’s joint all-time highest scorer with Marek Hamsik.

The two sides were facing each other for the first time and Barcelona’s struggle was evident and they will consider themselves lucky to have earned an away goal.

The beginning of the second half, though, displayed an urgency in Barcelona’s approach. Their efforts finally paid off when Griezmann fired home from a close range to successfully break the Napoli defence.

The home team, meanwhile, almost took the lead back as they responded with a string of attacks. Touring goalkeeper Marc-Andre Ter Stegen denied Lorenzo Insigne and Jose Callejon to keep his team alive in the encounter.

The misery lasted for the visitors till the very last moments as Arturo Vidal was sent off in the penultimate minute of the regulation time after he picked up two yellow cards in quick succession.

Another concern for the Quique Setien-managed team was the injury of Gerard Pique, who limped off the ground after falling heavily on his ankle. With the La Liga Classico against Real Madrid looming large, Pique’s availability for the match remains highly doubtful.