The two-time defending champion retired in the third set of her quarterfinal against Kazakhstan's Elena Rybakina due to a right thigh injury, news outlets reported.
The two were tied 2-2 in the third set when the 21-year-old Pole called it quits after more than two hours of play, Polish state news agency PAP reported.
Świątek had won the first set 6-2 and lost the second 6-7.
The defeat against Rybakina ended Świątek's 14-match winning streak in Rome, according to the wtatennis.com website.
Świątek won last year's Italian Open. She also triumphed in Rome in 2021.
The 2023 Italian Open runs until Sunday.
(gs)
Source: IAR, PAP, wtatennis.com