Lionel Messi capped a night of unbridled joy with the 800th goal of his career as world champions Argentina celebrated their homecoming with a 2-0 friendly victory over stubborn Panama in Buenos Aires on Thursday.

The 35-year-old seven-time Ballon d'Or winner's stunning free-kick in the dying minutes came after 21-year-old MLS sensation Thiago Almada gave a glimpse of what the future holds with his first goal for the national team in only his third appearance.

It was an emotional night as fireworks crackled overhead before kick-off at the impressive Monumental stadium where the 83,000 lucky fans that managed to get tickets among the more than 1.5 million people who tried, created an electric atmosphere.

Messi, coach Lionel Scaloni and numerous players came onto the pitch with their children and several seemed on the brink of tears as fans in unison sung "Muchachos", the anthem of Argentina's victorious World Cup campaign in Qatar.

After the match the party continued, with every member of the World Cup winning squad given a replica trophy to lift, surrounded by their families.

"I always dreamt of this moment, being able to celebrate with you (the fans), being able to come to my country to lift a Copa America, a World Cup. It's the best thing there is," said Messi, who was presented with several awards after the game.

"I am eternally grateful to this group of players. Football is theirs, it belongs to all those that wear this jersey," said Scaloni, who finally cracked and let the tears flow.

"They leave every last drop of sweat and sometimes the result doesn't follow. This time it did and it's amazing."