Messi came into the contest with 99 goals for La Albiceleste having netted his 800th career goal, for club or country, in Thursday’s 2-0 win over Panama in Buenos Aires.
And 20 minutes into Tuesday’s friendly the 35-year-old reached triple figures, gliding past two defenders before firing in a right-foot low shot.
Messi added further goals to round out a hat-trick before half-time, also providing the assist for Enzo Fernandez’s strike as Argentina opened up a 5-0 lead.
That was Messi’s ninth international hat-trick, marking a run of 21 goals in 13 games for Argentina.
Among that run was Argentina’s World Cup triumph, where Messi scored in every game except the 2-0 win over Poland.
Messi is now the first world champion to 100 international goals, behind only Portugal’s Cristiano Ronaldo (122) and Iran’s Ali Daei (109) overall. Messi’s hat-trick means he now has 102.
Argentina rounded out the occasion by being presented with their World Cup trophy again, which Messi hoisted into the air with his teammates.
The players did another lap of honour as they celebrated with their fans in Santiago del Estero, in Argentina’s north.
“What a nice way to close these dates, impressive today all the people in Santiago del Estero,” Messi wrote on Instagram.
“I wish we can continue to share together many moments like these and that this craziness never ends!!!”