World No 4 and defending champion Alexander Zverev reached his 35th career final with a straight sets win over Pedro Martinez of Spain in Hamburg on Saturday.
Top seed Zverev eased to a 6-2, 6-4 victory as the 27-year-old booked a spot in a third consecutive clay-court final after Rome and the French Open.
Zverev now leads the ATP Tour with 44 wins this year, two ahead of top-ranked Jannik Sinner.
The German will face Arthur Fils in Sunday's final.
He has a 2-0 head-to-head record over the Frenchman, beating him in three sets on grass in Halle last month and in the semifinals in Hamburg in 2023.
"He's somebody that is extremely aggressive and he's somebody that is very young," Zverev said.
"He obviously has the talent, he has the potential to be one of the best players in the world, and it's up to him to realise his potential.
"Tomorrow I'm going to do everything that I can to prevent that, for him to make a step forward. But he's a great talent and there's nothing bad to say about him."
Fils, 20, defeated third seed Sebastian Baez 6-2, 6-2 in his semifinal.
"It was very hot, so it was very fast and my serve was working pretty well. That helped me a lot today and I don't know if tomorrow it will be that hot, but I hope so," said the world number 28.