Flavio Cobolli ended top seed Alexander Zverev's Munich Open title defence on Saturday as the Italian breezed past the world No 3 in straight sets to book his spot in the final.
Fourth seed Cobolli downed the home favourite 6-3, 6-3 in just under 70 minutes in their semifinal meeting.
The 23-year-old's blistering performance put paid to Zverev's hopes for a record fourth title on the red dirt in Munich.
Cobolli will face either American second seed Ben Shelton or Slovak qualifier Alex Molcan in Sunday's final.
"One of my best matches ever against one of my biggest friends on tour," Cobolli said.
"I'm a little bit shy when I play with a big player but today I played one of my best performances and I'm really happy."
Cobolli edged ahead of Zverev when he broke the German to love in the fourth game of the first set.
Zverev struggled to make inroads on Cobolli's serve over the course of the match, and when the world number 16 pounced on his opponent's first service game of the second set the writing was on the wall for Zverev.
Two punishing crosscourt forehands followed up by a crisp volley to finish off game seven secured Cobolli a double break and gave him the chance to serve for the match.
But Zverev hit back immediately as he secured his first break points of the encounter, converting at the second time of asking to halt his opponent.
A brilliant forehand on the run handed Cobolli match point in the next game and when Zverev framed a deep return the match was decided.
Cobolli advances to his second final of the season, where he will look to add to the title he picked up in Acapulco in February.