The ease with which Alcaraz dominated the No.5 seed, who was the runner-up at Roland-Garros in 2021, in the first two sets was astonishing.
His clash against Djokovic will be their second overall and first at a major. It pits a young champion versus a legend.
The eyes of the tennis world and beyond will be on Roland-Garros for the semi-final.
Story of the match
Shortly before the quarter-final, the camera was fixated on the combatants as they awaited their introduction to step onto Court Philippe-Chatrier.
Tsitsipas fiddled with his bag. Alcaraz, positioned to his left, was a bundle of energy.
He bounced from one leg to the other, mimed groundstrokes and looked ready to launch.
The contrast proved a truism of what was to unfold as the 20-year-old played with the haste of a man with a reservation booked for central Paris well before midnight.
Having fallen in all four previous meetings against the No.1 seed, including a final in Barcelona in April, the No.5 ranked Tsitsipas needed to start well. And he did.
In a fine flourish that promised more than eventuated, the Athens native fired three aces in the opening service game. But his challenge was defused immediately.