Alcaraz recovers from sluggish start to move into Monte Carlo last 16
After a mixed American tour, with a semi-final in Indian Wells and an early loss to David Goffin in Miami, the 21-year-old Spaniard made a successful return to clay.
His only previous appearance in Monte Carlo in 2022 ended in a three-set defeat by Sebastian Korda.
The 21-year-old Spaniard, ranked two in the world, made a slow start against the lively Argentine who outlasted him in extended cross-court rallies.
After gaining an early break, Alcaraz gave up four games in a row which was enough for Cerundolo to go on and take the set.