The 22-year-old Italian fourth seed was in a different class from the Argentine, spending just one hour and 52 minutes on court for the 6-0, 6-1, 6-3 romp.
It set him up for a fourth-round clash against Russian 15th seed Karen Khachanov, who made the semi-finals last year.
Sinner is yet to drop a set in his three matches so far, unlike the trio of players ahead of him in the rankings -- defending champion Novak Djokovic, Carlos Alcaraz and Daniil Medvedev.
"I do feel confident," he said. "I came here with a good off-season, preparation.
"I'm just quite focused and also relaxed on the court at the moment. Let's see how I handle the situation when the score is even or I'm down, how I react. It's going to be interesting to see."
Sinner enjoyed a breakthrough 2023, winning his first Masters title in Toronto and reaching the championship match at the ATP Finals, beating Djokovic in group play.
He then led Italy to the Davis Cup title, again toppling Djokovic along the way, to finish the year in the best form of his life.
The Italian advanced to the quarter-finals at the year's first major in 2022 and exited in the fourth round last year, but he has higher expectations this season after surging up the rankings.
First he must get past Khachanov.
"Every time we played, was very long matches, tough matches," Sinner said. "But this is why also I practise, to see where my level is, where I can find the right solution every time."