Tennis star Stefanos Tsitsipas has announced he has split from his father after tearing into him following defeat against Kei Nishikori on the ATP tour in Canada.

The Greek was looking to bounce back from his quarter-final defeat by eventual winner Novak Djokovic in the quarter-final of the men's singles in the Olympics in Paris.

He was competing in the last-32 of the men's singles, but lost in straight sets to the Japanese star, going down 6-4, 6-4 in Montreal on Wednesday night.

After, he launched a staggering outburst against his father - who is also his coach - Apostolos Tsitsipas, threatening to change his coach because of the way he said he has been treated.

Stefanos has gone ahead with the threat and parted company with his father, though he admits that his actions were a mistake. 

In a lengthy statement posted on X, he said: '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. 

'Philosophy teaches us that wisdom comes through understanding our limits and acknowledging our mistakes. In my case, I realized 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. My behavior on the pitch was unacceptable, and I feel disappointed that I got to a point where I showed a dark side of myself. 

'When I feel disrespected, judged, or emotionally attacked, I tend to lose control of what comes out of my mouth, which goes against my values ​​as a human being. I lost control and could not see clearly in front of me. 

'My father has been trying for the last few years to train me, raise me the right way and provide me with knowledge and wisdom, both on and off the field. I thank him for that. I thank him for the sacrifices, pain and suffering he has endured to make this endeavor a success. 

'From now on, his role will remain within the confines of the father role, and that alone. My father will continue to travel with me and be there to support me and provide assistance off the field, as I have always wanted. I have trusted my father with the coaching role for so many years, and I consider our partnership to be successful. 

'I'm not sure who will take his place, and I'm not in a position to decide yet. What I do know is that it is time to let this chapter and this phase close, and try to write a new one. We've both agreed to that and hope to focus on our human side first, then the rest. 

'Accepting my mistakes and trying to mend my ways is part of my path as an athlete, and I assure you that I will continue to work hard to improve myself, both on and off the field. I hope this experience is a lesson for me, and for everyone who struggles to find the right balance in their lives.'

Following his surprise defeat  against Niskikori on Wednesday, Stefanos said speaking about his father: 'I need and I deserve a coach that listens to me and hears my feedback as a player. My father hasn't been very smart or very good at handling those situations, it's not the first time he has done that.

'I'm really disappointed at him. I really don't know right now if I'd consider any changes, but I'm really disappointed. The most important thing for a player is to have direct and good feedback from a coach. The coach is not the one holding a racket. The player is the one trying to execute a game plan.

'It's a collaborative work that you put in together. It has to be reciprocal in order for me to try to develop my tennis. It's something I don't want to get stuck at that.'

Stefanos, who is ranked No 11 in the world, has suffered a number of shock defeats in recent weeks, including against Nishikori, who is ranked No 286 in the world.

At Wimbledon, he lost against Emil Ruusuvuori, who is ranked No 70, in the second round.

Apostolos has coached his son on and off since his childhood, but they have clashed before, including when Mark Philippoussis was briefly brought into the 25-year-old's team.

Stefanos has also clashed with his mother, Julia Apostoli, before, as she criticised her son's relationship with fellow tennis star Paula Badosa.

All four of Apostolos' sons play tennis, though Stefanos is the best.