Alexander Zverev outplayed Daniil Medvedev in a dominant display in Turin to win his second ATP Finals title.
The German world number three, who had lost to the Russian second seed in the group stage, turned the tables to win 6-4 6-4.
Zverev, the 2018 champion at the prestigious season-ending event, did not face a single break point.
"I had to play one of my best matches," Zverev said after his sixth title of a year that included Olympic gold.
"I'm super thrilled and super happy right now. There is no better way to end the season than to win here.