The American is in the Top-10 now, and eager to prove he belongs in 2023.
Stefanos Tsitsipas compounded his loss to Andrey Rublev with a stinging shot.
The 21-time major champion is showing his steel down the stretch in Turin.
"There was no illness. There was no particular part of the body that was bothering me," said former world No. 1 after grueling win over Daniil Medvedev.
The American hopes to finish 2022 with a strong weekend, but a menacing threat looms.
The 26-year-old reached No.1 in 2022, but ends the season losing eight straight against the Top-10.
Rafael Nadal isn't retiring, but suggested one event where he'd like to someday say farewell.