The 20-year-old continued his excellent start to the year, which included a run to the Australian Open semi-finals on the back of a fourth round defeat of Roger Federer, by battling to a 7-5, 7-6 (7/5) victory.
“Winning titles is the thing that I am working for… It is the biggest satisfaction and the biggest joy in tennis,” said Tsitsipas, who won his first ATP title in Stockholm last year.
“There was a lot of stress this week because I knew I had to face some good opponents.
“When you care a lot, you tend to be more stressed than usual. I am happy that I got through that stress and played the game that I was supposed to play.”
Tsitsipas went into the week having lost his last two matches to Gael Monfils and Damir Dzumhur, but cruised to the title without dropping a set.
“I lost the spark (after the Australian Open) and I was frustrated because it felt like I couldn’t find it again,” said Tsitsipas.
“This week, I can say I am really happy because I felt this hunger back again… I really hope it stays the same because there are many good players out there that play for the same prize.”
On Sunday, Tsitsipas edged a tight opening set with the first break of the match in game 12, before falling a break behind midway through the second set.
But Kazakh Kukushkin failed to serve for the set when leading 5-4, and Tsistipas pounced to seal victory on his first match point in the tie-break.
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