World number 12 Marin Cilic has split with coach Goran Ivanisevic after less than three years together.
Under Ivanisevic's guidance, Cilic claimed the 2014 US Open for his one and only grand-slam success.
Cilic recently reached the Wimbledon quarter-finals, but announced the end of his partnership with Ivanisevic - a former champion at the All England Club.
"Unfortunately, I am no longer working with my coach Goran Ivanisevic," the 27-year-old wrote on his website.
"We have started to work together in September 2013 and we had a lot of success during that period, especially winning the US Open in 2014.
"It was huge privilege to work with Goran, I enjoyed our work all this time and Goran helped me to reach many goals.
"Unfortunately, the road we were sharing on this journey is separating and I wish only the best for Goran in the future."