Holger Rune was on the end of an upset as he lost 7-6 (8-6) 6-4 to Giovanni Mpetshi Perricard at the Swiss Indoors Basel. (More Tennis News)
Mpetshi Perricard has soared into the top 50 after starting the year ranked at 205, and the Frenchman was on top form against his fellow youngster on Saturday.
He served 17 aces to get the better of Rune and tee up a final against American Ben Shelton.
"It's amazing to be in the final. I played a good match today. It was difficult against Holger, but I found the key to win this match," said Mpetshi Perricard.
"Inside of me there was a lot of emotion, but I tried to calm it down. It's nice to be in the final and I hope to get the win."
Shelton, meanwhile, beat Arthur Fils 6-3 7-6 (11-9).
At the Vienna Open, Jack Draper ensured his place in the top 15 of the ATP rankings and reach the first ATP 500 final of his career by overcoming Lorenzo Musetti 6-2 6-4.
Musetti downed favourite Alexander Zverev to reach the last four, but the Italian was no match for Draper, despite the Briton letting a 4-2 lead slip in the second set.
"I thought the first set was a really high level from my side," said Draper.
"Lorenzo is a really tough competitor. I've known him since I was really young and playing against him is always so difficult. He's had an incredible season.
"The second set was really up and down. There were some long points and definitely some nerves and difficult moments, but I'm really proud of the way I kept on fighting and kept on going. In the end I got it done."
Karen Khachanov will be Draper's opponent in the final, after the Russian overcame Alex De Minaur.
