Messi and Medel confronted each other with Argentina 2-0 up in the game in Sao Paolo after goals from Sergio Aguero and Paulo Dybala.

The Argentine star and Chile skipper Medel squared up near the touchline after the ball ran out of play in the 37th minute.

Both barged each other with their chests before Medel appeared to lower his head toward the Barcelona star as teammates ran in to break the pair up.

Paraguayan referee Mario Diaz de Vivar then ran over to brandish red cards to both players.

Social media users were quick to jump to Messi’s defense over the incident, many labelling the decision ridiculous.

While Argentina were well-placed for victory, the sending off marks yet more woe for Messi on the international stage.

Defeat to Brazil in the semi-final meant that Argentina extend their wait for a first major title since 1993, while Messi again will not taste Copa America victory after missing out in the final in the last two editions of the competition.  

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Messi had earlier raged at the officiating in the tournament, and would appear to have more cause for grievance after the latest decision.  

Saturday's red card was Messi's second in his Argentina career - his first coming on his debut after just 44 seconds against Hungary 15 years ago.