Shanghai - Daniil Medvedev tamed self-styled "wild horse" Fabio Fognini 6-3, 7-6 (7/4) to canter into the Shanghai Masters semi-finals on Friday.
The in-form Russian world No 4 plays top-ranked Novak Djokovic or young Greek Stefanos Tsitsipas on Saturday in the last four.
Italy's Fognini, 12th in the world, was broken in the sixth game of the first set when he double-faulted.
The second set went to the tie break and despite Fognini taking a 2-0 lead, Medvedev pulled back in front with his serve a major weapon.
The 23-year-old sent down 12 aces to Fognini's three in the match.
Medvedev is in scintillating form, having reached a staggering eight finals this year including at the US Open.
He was beaten at Flushing Meadows by Rafael Nadal in five sets.
Medvedev is chasing a fourth title in his breakthrough season.