The top seed claimed the title by winning all five of his matches during the week, to succeed South Korea's Chung Hyeon, who won the inaugural edition previous year in which Tsitsipas only played an exhibition match.
The NextGen Tournament heads for the final in Milano as the top eight ranked male players gather in London for the ATP Tour Grand Finale, while the female players from Czech Republic and the United States are in Prague, for the final of the Federation Cup.
Despite his tender years, De Minaur has already established himself as one of the pluckiest fighters on the ATP Tour, while he boasts breathtaking speed - much like his mentor and two-time Grand Slam champion Lleyton Hewitt. "Because it was still one set to go and it was anyone's game".
After the match, the Greek sensation said: "It feels great".
Both players had only dropped a set apiece in their first three matches at the tournament but each needed five sets to win their respective semifinals on Friday.
Meanwhile, Tsitsipas is now scheduled to lock horns with Alex De Minaur of Australia in Sunday's final. "I had a chance twice to win the match, but remained calm".
"I've played some incredible tennis throughout the whole year".
Earlier on Saturday, Russia's Andrey Rublev won the third-place play-off, defeating Spain's Jaume Munar 1-4 4-3 (7-4) 2-4 4-2 4-3 (7-3) to end what's been a tough season on a high. Look, for example, the match today of Tsitsipas that make incredible season beating top players, and now - I'm not saying nothing bad about Munar.
He said winning the final would be "the cherry on top of an unbelievable season for me".
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