Johanna Konta has split from Spanish coach Esteban Carril.
The news comes as a surprise given the 25-year-old's meteoric rise under the guidance of Carril.
There has so far been no comment from Konta or her agent but Carril confirmed the split in an email to Press Association Sport.
Konta turned to Carril, who is the director of an academy in Gijon, after having her funding cut by the Lawn Tennis Association.
At that stage, Konta was ranked outside the top 100, but her rapid rise began in the summer of 2015 when she reached the fourth round of the US Open as a qualifier.
She began 2016 with a stunning run to the semi-finals of the Australian Open and has continued to climb the rankings since, finishing the year as the first British woman to be ranked in the top 10 since Jo Durie 32 years ago.
Carril also introduced Konta to mental coach Juan Coto, whose influence has arguably been even more important in helping her overcome performance anxiety.
Konta, who was named the WTA's most improved player for 2016, will begin next season at the Shenzhen Open in China, starting on January 1.
News of the split comes hot on the heels of Milos Raonic's announcement that he will no longer be working with another Spaniard, former world number one Carlos Moya.
Moya joined Raonic's team at the start of the year and helped the Canadian to the best season of his career, capped by a Wimbledon final appearance and ascent to world number three.
Raonic wrote on Instagram: "Thank you to Carlos Moya for helping me tremendously this year, alongside my team, to get the best out of me.
"Under Carlos' direction and tutelage I have played my best yet to date. We will no longer be continuing our coaching relationship but remain close friends. I wish him all the best."
Raonic, who was also advised by John McEnroe this year, will continue to work with his main coach Riccardo Piatti.
As well as Raonic and Konta, Madison Keys, Elina Svitolina, Kristina Pliskova and David Goffin have all parted company with coaches after career-best years.
Source: PA
