Hyeon Chung claimed the inaugural Next Gen Finals title by coming from behind to beat top seed Andrey Rublev in Milan on Saturday.
Chung defeated Rublev for the second time this week to claim his maiden ATP World Tour title, winning 3-4 (5-7) 4-3 (7-2) 4-2 4-2.
The sixth seed from South Korea made it five wins out of five in the tournament to be crowned champion, outlining his promise and ending the season on a high note.
Chung, 21, saved seven break points and secured the only break of the fourth set - his fourth of the night - to see off the 20-year-old Russian.
Daniil Medvedev took third place after Borna Coric withdrew from their scheduled match.
Medvedev ended up having a knock with tournament director Ross Hutchins and the ball kids when an exhibition match with Denis Shapovalov was cancelled due to an injury picked up by Canadian.