Argentina began their 2019 Copa America campaign in Brazil with a 0-2 loss to Colombia on Saturday.
Goals from Roger Martinez and Duvan Zapata in the final 20 minutes earned the Tricolours their first victory over the two-time World Cup winners in 12 years.
Lionel Scaloni’s Argentina had dominated possession and territory but never really threatened David Ospina too much in the opponents’ goal.
Argentina have finished runners-up in this competition for the previous two additions and have not lifted the trophy since 1993. They have not done themselves any favours by starting with defeat, but face Paraguay and Qatar in their final two group games, with the top two from each group guaranteed of progressing, as well as two of the three third place teams.
Lionel Messi missed his nation’s best chance of score when he headed a rebound wide following Ospina’s save from centre-back Nicolas Otamendi.
Colombia, managed by former Portugal and Real Madrid head coach Carlos Quieroz, scored both of their goals against the run of play in the final 20 minutes.
Substitute Martinez cut in from the left and drove his 20-yard effort into the top corner across goal in the 71st minute after being set up by James Rodriguez.
Zapata, who scored 23 Serie A goals in helping Atalanta qualify for the Champions League for the first time last season, sealed the win with a late close-range effort, having replaced captain Radamel Falcao.
Argentina face Paraguay next, who begin their campaign against invitees Qatar on Sunday. Colombia face Qatar on Sunday too.