Jannik Sinner became the first Italian to reach the final of the ATP Finals by taking a gutsy 6-3, 6-7 (4-7), 6-1 victory over Daniil Medvedev.
Sinner, 22, was fired up by the home support in Turin and saw off the Russian in two hours and 29 minutes.
He will face Novak Djokovic or Carlos Alcaraz, who meet in their semi-final on Saturday evening, in Sunday's final.
"It is a privilege to have this kind of pressure. The crowd has given me so much energy," Sinner said.
"It is an incredible feeling because it was a really tough match.