Stefanos Tsitsipas outlasted Poland's Hubert Hurkacz on Thursday in three sets to reach the Rotterdam quarterfinal.
He dropped the second set but won in a tight decider on his third match point, securing a 6-4, 4-6, 7-5 victory.
"I played really well. Both of us, we played a high level of tennis and didn't give many break-point opportunities," Tsitsipas said in his post match interview.
"There were pretty good serves from both sides and I am really glad that I fought so hard towards the very end. It was exhausting, but it paid off."
Greece's star will now face Russia's Karen Khachanov on Friday for a semi-final spot.
Stefanos Tsitsipas is an inspiration and champion on and off the court.
Earlier this week he announced that he will donate €3,000 to ‘Mazi gia to Paidi’ for every doubles win with his partner, his brother Petros.
“I donate anyways, but I think that’s an extra reason to push ourselves, to want to do better,” he said.
Stefanos has been an ambassador for the charitable organisation since 2018.
Founded in 1996, ‘Mazi Gia to Paidi’ (Together For Children NGO) is a non-profit Association, offering every form of assistance to children and young people irrespective of their race, religion or political conviction.
They support more than 30,000 children on an annual basis, including more than 10,000 direct children beneficiaries, who face poverty and social exclusion, domestic violence, chronic diseases, mental or physical disabilities and the sickness or death of an immediate family member.