Stefanos Tsitsipas beat Casper Ruud 6-1 6-4 to win his third Monte Carlo Masters title in four years.
Greece's Tsitsipas, 25, dominated the opening stages and sealed the first set inside 36 minutes.
Norwegian Ruud fought valiantly in a tense second set, which was level at 4-4 before Tsitsipas pulled away in the final two games.
"It's been a very difficult time for me, so to be back on the podium and winning, it's amazing," he said.
The victory took Tsitsipas to seventh in the world rankings and he fell to the floor in emotion after his win.