Wimbledon champion Swiatek, the world No.3, is just a couple of places above the American Pegula in the rankings, but the gap between them appeared vast as the Pole took just 67 minutes to win 6-1 6-2 on a damp Wednesday morning in Rome.
Swiatek's impressive form bodes well for the upcoming French Open, where she'll be hunting for a fifth title.
In the last four, she will next face another former Rome champion Elina Svitolina, who fought back to defeat the in-form world No.2 Elena Rybakina 2-6 6-4 6-4.
Three-times Rome champ Swiatek has also put herself in line for a possible showdown with reigning Roland Garros champion Coco Gauff on Saturday, with the American to face .
Swiatek hasn't won a clay-court tournament since Roland Garros in 2024, but with her new coach Francisco Roig on board, appears to have switched into her old form at the Foro Italico, having demolished Naomi Osaka and now Pegula in magisterial fashion.
Swiatek reached the quarter-finals in Stuttgart last month but had to retire from the Madrid Open with a viral infection, but she looked in the mood to lift a fourth Italian title with her brilliant display.
"I'm happy that I can spend some time on the court and play really solid matches against the best girls," Swiatek said.Â
"For sure it's giving me confidence because you can practice as much as possible, but if you don't test it out on the court, play matches and face pressure or something, you're going to still feel the little bit rusty when it comes.
"Now I'm happy I played couple matches. I'll play hopefully two more here."
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