Paris - Kevin Anderson's Paris Masters campaign was ended by Japan's Kei Nishikori on Thursday night.
Nishikori, seeded 10, made the quarter-finals by beating the seventh-seeded Anderson 6-4, 6-4 to avenge his defeat to the big South African in Sunday's Vienna final.
Nishikori will now face 20-time Grand Slam winner Roger Federer, who defeated Italy's Fabio Fognini 6-4, 6-3.
The Swiss great moved three wins away from his 100th career title.
Third seed Federer is playing the Paris Masters for the first time since 2015 and is bidding to clinch the tournament for just the second time after winning it in 2011.
"I didn't come here to win Paris, actually. My objective is London," said Federer as he looked beyond the French capital to the season-ending ATP World Tour Finals which start on November 11.
Federer leads Nishikori 6-2 in career meetings having won their last four clashes. The Japanese's last win over the 20-time major winner came in 2014.
Anderson, meanwhile, will no shift his attention to the prestigious ATP Finals which take place in London between November 11 and 18.
Results from the ATP Paris Masters on Thursday (x denotes seeding):
Jack Sock (USA x16) bt Malek Jaziri (TUN) 6-0, 6-4
Dominic Thiem (AUT x6) bt Borna Coric (CRO x11) 6-7 (3/7), 6-2, 7-5
Alexander Zverev (GER x4) bt Diego Schwartzman (ARG x15) 6-4, 6-2
Karen Khachanov (RUS) bt John Isner (USA x8) 6-4, 6-7 (9/11), 7-6 (10/8)
Kei Nishikori (JPN x10) bt Kevin Anderson (RSA x7) 6-4, 6-4
Roger Federer (SUI x3) bt Fabio Fognini (ITA x13) 6-4, 6-3
Marin Cilic (CRO x5) bt Grigor Dimitrov (BUL x9) 7-6 (7/5), 6-4
Novak Djokovic (SRB x2) bt Damir Dzumhur (BIH) 6-1, 2-1 - retired