Daniil Medvedev was a set down against Novak Djokovic, but he rallied to stunning 3-6 6-3 6-3 semi-final victory in Cincinnati on Saturday.
Daniil Medvedev and Novak Djokovic will meet in the semi-finals, while David Goffin and Richard Gasquet are set to clash.
Lucas Pouille produced an impressive display but it was still not good enough as world number one Novak Djokovic prevailed on Friday.
Nick Kyrgios was fined $113,000 (£93,254) for five separate offences in Cincinnati and Andy Murray says he must change his ways.
Having undergone hip surgery in January, Andy Murray is still on the long road to recovery and will not feature at the US Open.
Novak Djokovic eased into the Western & Southern Open quarter-finals, but Roger Federer crashed out.
After an early singles exit in Cincinnati, Andy Murray accepted a wildcard into the Winston-Salem Open.
Novak Djokovic eased past Pablo Carreno Busta to reach the Western & Southern Open quarter-finals.
Roger Federer's US Open preparations took a hit as the world number three suffered a shock Western & Southern Open defeat to Andrey Rublev.
Nick Kyrgios let his volatile side rise to the fore as he verbally abused an umpire and smashed two rackets, costing him a big ATP fine.