The 39-year-old captain delivered one last masterclass in his final appearance for Argentina, setting up Nicolas Otamendi for the opener, then Nico Paz for the second, before converting a penalty for the third and his 126th international goal.
The match was less about football than a national farewell. More than 85,000 fans packed the stadium, waving flags and chanting Messi's name throughout. His family watched from the stands alongside Argentina's World Cup winners from 1978, 1986 and 2022.
"Even through the worst moments we went through, I never stopped fighting, battling, giving everything I had, wanting to always be here," Messi told the crowd after full-time. "I love all of you, and I will miss all of you. I am proud to be Argentine."
The emotion began hours earlier in Rosario, Messi's hometown, where a massive number 10 shirt emblazoned with "Gracias" was unfurled at the National Flag Memorial. Thousands lined the team bus route, and Messi wiped away tears as he passed.
Benin captain Sessi D'Almeida appeared lost for words as he handed Messi a gift and letter during the pre-match handshake. The crowd rose for applause and fireworks erupted past the 10th minute, a tribute to the number Messi has worn throughout his career.
Otamendi, who shared 17 years and four World Cups with Messi, also ended his international career. Messi leaves as Argentina's most-capped player (208) and record scorer, having turned years of international frustration into World Cup and Copa America triumphs.
"For years, Argentina asked Messi to deliver," the match report noted. "On Tuesday, it simply came to say thank you."