Russia's Andrey Rublev overcame Grigor Dimitrov 7-6(7), 6-3 in their semi-final clash at the Shanghai Masters on Saturday, and will now face Hubert Hurkacz, who beat Sebastian Korda.
Rublev, the fifth seed, needed to save a set point before winning a 76-minute opening set in a tie-break against his good friend.
"It's not easy when you win matches against friends, because you feel both sides," Rublev said.
"You feel sad, but at the same time you want to win. It's a mix of feelings."
Dimitrov had knocked out top seed Carlos Alcaraz earlier in the tournament, and the Bulgarian broke serve early in the second set to take a 2-0 lead over Rublev.
With Dimitrov 2-1 up and with a 40-15 lead on serve, Rublev looked in trouble, but the Russian rallied to win that game, and after that took control to see out the match.
Rublev can move up to number four in the ATP rankings, his highest ever position, if he wins the Shanghai Masters, but he will first need to see off strong-serving Hurkacz.
The Pole lost his last meeting with Korda at this year's Australian Open, but eased to a 6-3, 6-4 semi-final win over the American on Saturday.
Hurkacz hit 14 aces and dominated on serve, and one break of Korda's serve in each set was enough for the 16th seed to reach the final.
"I'm just really happy with my performance today," Hurkacz said. "I was serving well, playing some good groundstrokes and definitely putting pressure on Sebi from the ground."
Korda caused an upset when defeating second seed Daniil Medvedev on his way to the semi-final, but was unable to deal with Hurkacz's pace and precision.
After wrapping up victory, Hurkacz took a marker-pen and wrote 'thank you' in Chinese on the TV camera in appreciation of the crowd's support.
Rublev and Hurkacz face each other on Sunday, having both won twice in their four previous meetings.
"He's one of the players that you don't want to face because he can beat everyone. With his style of the game, the way he serves, the way he hits the ball," Rublev said.
"We'll see, I just want to take my time to recover and to be as ready as possible for tomorrow."
