The midfielder let loose a perfectly-placed effort 10 minutes into the game, and an impeccable performance in goal from Barovero puts the Liniers side in the Copa driving seat
The Fortin were disciplined and organised throughout, and against a lacklustre Colombian side were boosted by the winger's exquisite early finish to take a commanding position in the continental competition. Nacional disappointed in front of their own fans, and aside from the always dangerous Dorlan Pabon lacked the imagination and flair to overcome their opponent's tireless defending.
Nacional came out with pace and purpose in the Atanasio Girardot, looking to take the initiative by pressing across the pitch. Velez, meanwhile, were content to sit back in their own half and let the Colombians come to them; but the tactic almost backfired with barely five minutes on the clock. A precise pass from Macnelly Torres released Dorlan Pabon, only for the striker to be denied by Marcelo Barovero clean through on goal.
In their first attack of the match, however, the Fortin found themselves in the lead. Juan Manuel Martinez expoited a moment of inattention from the Nacional defence to chip the ball through to Ivan Bella; and, bearing in from the right flank, the midfielder let loose a delightful shot which beat Gaston Pezzuti and settled inside the post for the opening goal.
The Medellin side kept probing, but struggled against a committed Velez defence buoyed by the early away goal. Pabon was the Verdolago's best outlet going forward, and a snapshot on the left hand side gave Barovero a momentary scare before smashing into the side netting.
Velez should have gone two up when a slick counter-attack led to Lucas Pratto losing out to an inspired Pezzuti stop, while a long-range effort from Pabon fizzed agonisingly over the bar to make sure the Argentines went into the break with a slim lead.
The visitors came out for the second period with an increased commitment at the back, packing bodies behind the ball to frustrate Nacional's notoriously lethal forward line. Even 'Burrito' Martinez saw action deep in his own half, as holding on to a potentially massive victory became imperative for Velez. But Ricardo Gareca's men were still dangerous on the break, and only a fantastic penalty stop from Pezzuti denied Martinez from doubling the advantage after the forward himself had been chopped down.
Minutes later Barovero proved once more to be Pabon's nemesis. The Colombia international showed electric pace to leave the Velez defence standing, but the goalkeeper's left foot diverted away the shot to thwart Dorlan once more one on one. It would not be the last time either, as the forward peppered strikes from across the pitch on goal only to be denied time and again by Barovero.
Nacional continued to press forward, but despite several further dangerous forays into Argentine territory could not find the strike that would have sent them to Liniers on level terms. The teams will meet for the second leg on May 8, in Velez's Jose Amalfitani home.