Spanish teenager Carlos Alcaraz will become the youngest player in the top five of the ATP rankings since Rafael Nadal in 2005 after reaching the Hamburg Open final.
The Miami Open and Madrid Open champion has won his five previous Tour finals.
"I have a lot of confidence for the final and hope to make it six-for-six," said Alcaraz after his latest clay win.
"Lorenzo is playing really well. It's going to be a great final."
Nadal was under a month away from turning 19 when he became fifth in the world for the first time.