The Spaniard needed just one hour 34 minutes to dismantle former world number nine Paul 6-0, 6-1, 6-4 and set up a last-four meeting with Italy’s Lorenzo Musetti.
Musetti, seeded eighth, earlier beat Paul’s compatriot and 15th seed Frances Tiafoe in four sets.
It will be the third time Alcaraz and Musetti meet this clay-court season.
Alcaraz has dominated that series, beating the Italian in the final in Monte Carlo before also stopping him in the last four on his way to the Rome title.
And the 22-year-old’s blistering performance under the lights on centre court in Paris will have many backing him to make it three from three against Musetti as he seeks to defend his title.
“It was, I could close my eyes and everything went in, my feeling today was amazing. Today was one of those matches where everything went in, I’m just pleased with everything,” said Alcaraz.
Alcaraz fired 40 winners on his way to victory over Paul for just 22 unforced errors as he emphatically put inconsistent displays in the previous rounds behind him.
“This kind of match is never easy,” he said. “I’ve played Tommy many times and he’s beat me twice.”
Despite previous success against Alcaraz, it took the 28-year-old American eight games to get on the scoreboard as his opponent raced out of the blocks, mixing powerful groundstrokes with perfectly-weighted drop-shots and lobs.
Paul put up determined resistance in the third set but couldn’t deny Alcaraz, who broke in the ninth game before holding to love for victory.
“I know you wanted to watch more tennis,” an apologetic Alcaraz told the crowd on centre court. “I have to say sorry for that. But I had to do my work.”
Paul has now lost his last four meetings with Alcaraz, including at the same venue last year in the last eight of the Olympic Games. (AFP)