Inter Miami star Lionel Messi had one-word message after Argentina's Olympic Game opener against Morocco ended in a dramatic fashion.

La Albiceleste began their campaign with a defeat against the North African giants in an unprecedented football match that ended after four hours in Saint-Etienne.

Down by 2-1 after 90 minutes, Argentina equalized in the 106th minute of added time, following a surprising 15-minute stoppage time addition.

However, Cristian Medina's late equalizer was ruled out for offside after a nearly two-hour interruption which was sparked by angry Moroccan fans entering the stadium.

The game resumed as Argentina's late equalizer was ruled out for offside with Morocco securing a hard-fought 2-1 victory.

The controversial game has sparked divided opinions among fans on social media.

Messi, currently recovering from an injury sustained during the Copa America final, added his voice to the debate.

On his Instagram story, the Argentina captain simply wrote: "Unbelievable."