Although Messi's club colleague Arturo Vidal pulled a goal back for Chile with a second-half penalty, Argentina held on to claim third place at the expense of the team they lost to in the 2015 and 2016 finals. This year's Copa America champions will be Peru or the hosts Brazil, who will meet in Sunday's showpiece fixture at the Maracana Stadium in Rio de Janeiro (kick-off 21:00 BST).
Alexis started all of Chile's six games in the tournament and finished it with two goals to his name - against Japan and Ecuador in the group stage.