Amid the unprecedented number of seeded players suffering early exits this week, Sinner has looked untouchable in his five hours and 23 minutes on court.
Martinez, aiming to reach the fourth round of a major for the first time, was seeking to cause a remarkable upset of his own, but against a player who has lost only once to an opponent ranked outside the top five seeds in his four Wimbledon appearances.
The efficiency with which Sinner continues to despatch his lower-ranked opponents has ensured this part of his tournament has felt a near-formality as he effortlessly closes in on an expected semi-final showdown with Novak Djokovic.
He cruised through to this stage, losing just five games against Aleksandar Vukic and seven to Luca Nardi, and once again never appeared under threat on Saturday against Martinez.
Sinner lost just six points in his four service games as he took only 37-minutes to capture the first set, which also included a medical timeout for Martinez to receive treatment for a shoulder problem.
Despite struggling physically, the Spaniard offered resistance at the start of the second with consecutive holds of serve, and again when he admirably battled his way to four break points after falling a break of serve down.
But he was ultimately powerless to stop Sinner closing out another set, before the top seed sealed victory by storming to the finish line.
Sinner has continued to show remarkable consistency over the past 22 months, losing just 11 of 125 matches since the Beijing Open in September 2023.
Almost half of those defeats have come in his past five meetings with Carlos Alcaraz, the defending Wimbledon champion and seeded second at the Championships.
But the Italian will increasingly believe this stellar form can lead him to avenge his painful French Open final loss to Alcaraz – should his Spanish rival also progress to next week’s showpiece as widely expected.