Top seed and four-time champion John Isner will face Ryan Harrison in Sunday's Atlanta Open final.
It was not the easiest of semi-final wins for Leonardo Mayer, but he has a shot at a third German Tennis Championships triumph.
Youth was the winner of the day in the Moscow River Cup semis, as Olga Danilovic and Anastasia Potapova reached Sunday's final.
John Isner set up a semi-final clash with Matthew Ebden after defeating Mischa Zverev in three sets at the Atlanta Open.
Each of the top three seeds, including Austrian star Dominic Thiem, crashed out of the German Tennis Championships on Friday.
Julia Goerges and Anastasija Sevastova - the top two seeds left in the Moscow River Cup - both exited at the quarter-final stage on Friday.
Ahead of appearing at Washington DC's Citi Open, Andy Murray appeared to mock Donald Trump over his comments on freedom of speech.
Nick Kyrgios needed just 56 minutes to dismantle American qualifier Noah Rubin 7-5 6-2 at the ATP 250 tournament on Thursday.
Daria Kasatkina crashed out of the Moscow River Cup to Tamara Zidansek, who survived a fightback from the second seed.
While Dominic Thiem led the seeds through at the German Tennis Championships, the big names faltered in Switzerland.