Stefanos Tsitsipas ended his long-time coaching collaboration with his father on Friday, announcing the decision on social media.
"It is with a heavy heart that I inform you that my collaboration with my father as a coach has come to an end. I prefer to keep my father in his role as a father, and only as a father," the world number 11 from Greece posted.
Tsitsipas dropped a huge hint of the split on Thursday after losing 6-4, 6-4 to Japan's Kei Nishikori in the ATP Montreal Masters second round.
The 25-year-old, who once stood third in the world, complained in defeat that his father Apostolos was not listening to him and was not providing the proper coaching motivation and input.
"Philosophy teaches us that wisdom comes through understanding our limits and acknowledging our mistakes," the younger Tsitsipas posted.
"In my case, I realised that I was wrong to talk to my father the way I did. Tennis is not just a match, a hit or a performance of a few seconds. It is a long journey full of emotions, pressure and expectations.
"In that moment of frustration, there were many mistakes and errors on the part of my coach and father.
"As an introvert, I tend to hold in my emotions and build them up until I reach a bursting point. I consider myself patient, so the fact that I reacted this way left me shocked."
Tsitsipas brought in another coach in 2023, staying under the wing of former Wimbledon and US Open finalist Mark Philippoussis for a few months before parting and returning to his father as mentor.
The Greek has just one title this season, repeating as Monte Carlo champion for a third time.
He added that while he has yet to select a replacement coach, his father will remain part of his team off the court.