The 34-year-old had a hand in all three goals, providing the assist for the first two before rounding up proceedings with a stunning freekick in injury time.
Lionel Messi's star performance means that he has now scored four goals in as many matches at the tournament and is the runaway favorite to win the 2021 Copa America Golden Boot.
The closest challenger to Messi in the Copa America Golden Boot race is former teammate and Brazil star Neymar, who currently has two goals. Several other players on two goals have since been eliminated from the tournament.
n addition to his four goals, Lionel Messi also has a further five assists in what has been a stellar performance so far in Brazil.
The Rosario native kickstarted the tournament with a direct freekick in the 1-1 draw with Chile before drawing blanks in narrow 1-0 victories over Uruguay and Paraguay.
He followed up with a brace and an assist in the 4-1 demolition of Bolivia in the final group stage game before another star performance against Ecuador on Sunday.
The victory means Argentina will trade tackles with Colombia on Wednesday for a place in the final of the Copa America.
Lionel Messi is currently without a club, having seen his deal with Barcelona expire at the end of June. While his future may be uncertain at club level, his performance at the Copa America has been assured.
Could Lionel Messi be the catalyst to end Argentina's Copa America drought?
Argentina are one of the most traditional sides on the international scene but La Albiceleste have not tasted success in international tournaments since 1993.
The 28-year drought is far from ideal for a side of Argentina's standing and has been exacerbated by the caliber of players available to the nation since then.
However, Lionel Scaloni's appointment as manager has seen the national team revamped and a new crop of players have helped reinstill confidence in the side.
Lionel Messi remains the driving force behind his country's resurgence and the six-time Ballon d'Or winner's performance in the 2021 Copa America underlines his determination to end his nation's trophy drought.
Brazil might be favorites to retain their Copa America title but with Lionel Messi in this form, Argentina will fancy their chances of going all the way.
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