Alcaraz’s victory puts him on track for a repeat quarter-final against Italy’s Jannik Sinner, a year after the two men staged an epic duel in a five-hour five-setter that ended at 2.50am, the final of the US Open. was the latest finish in history.
Sixth-seeded Sinner played his part in securing the rematch with an impressive 6-3, 2-6, 6-4, 6-2 win over Swiss veteran Stan Wawrinka on Saturday.
Meanwhile, Arnaldi, Alcaraz’s last-16 opponent, went on to beat 16th-seeded Briton Cameron Norrie, winning 6-3, 6-4, 6-3 in just under two hours.
The 22-year-old Arnoldi, who had never played in the main draw of a Grand Slam before this season, had his best performance at a major championship with a brief run to the second round at Roland Garros.