Rio de Janeiro, Jun 15 (IANS): Eduardo Vargas extended his impressive Copa America scoring run with a second-half header that earned Chile a 1-1 draw with Argentina.

Lionel Messi gave Argentina the lead at Rio de Janeiro's Olympic Stadium on Monday by curling a free-kick over the wall and into the top right corner just after the half-hour mark.

Argentina threatened to score again, laying siege to Claudio Bravo's goal, but the two-time world champions were unable to capitalise on their superiority, reports Xinhua.

Vargas made them pay when he nodded home in the 57th minute, reacting fastest after Aston Villa goalkeeper Emiliano Martinez kept out Arturo Vidal's spot-kick.

The Atletico Mineiro forward has now scored 13 Copa America goals and sits joint sixth on the tournament's list of all-time highest scorers.

"We lacked tranquility," Messi said after the match.

"The (state of the) pitch did not help. We were unable to control possession and play faster, which they did. I did not see the penalty but it changed the game.

"I think that the (result) gives them more peace of mind than us. They started to pass the ball around and to keep it off us and the game became difficult. We wanted to start with a win but we came up against a very tough opponent."

Argentina's next match will be against Uruguay in Brasilia on Friday while Chile faces Bolivia in Cuiaba on the same day.