The Spanish star, seeded second, put on a dominant show to brush aside the 55th-ranked Argentinian in the second round in just 66 minutes.
"Really, really happy with the way I played today. It wasn't easy," said the 23-year-old former number one.
"Just had two days of preparation... I came from Tokyo, there were totally different conditions," he added. "Just tried to play the best that I can."
Sporting a fresh moustache, Alcaraz signed a camera "Moustache Team" following his win.
Asked by an on-court interviewer about the new look, Alcaraz said: "It's gonna stay."
He will play either Ignacio Buse or Zizou Bergs in the next round.
World number five Felix Auger-Aliassime also survived a scare, needing three hours to beat 77th-ranked Camilo Ugo Carabelli 4-6, 7-6(1), 7-5.
The Canadian will play Spaniard Pablo Carreno-Busta in the third round.
Several matches in the afternoon were suspended due to rain, but Taylor Fritz, Casper Ruud and Arthur Fils all went through as play resumed.