Caroline Wozniacki has fired coach Ricardo Sanchez, just two months after employing the Spaniard.
Sanchez, who previously worked with Jelena Jankovic, teamed up with the Dane at the beginning of December.
Although the pair were targeting glory at the Australian Open, the 21-year-old was beaten in the quarter-finals by Kim Clijsters, surrendering her world number one ranking in the process.
Wozniacki has now been relegated to fourth place in the WTA rankings behind Maria Sharapova, Petra Kvitova and Aussie Open champion Victoria Azarenka.
Piotr Wozniacki, Caroline's father, will now coach the star once again.
Sanchez cited Piotr's continued involvement during his time with Wozniacki as a major stumbling block to their success.
He told Sky Sports News: "Caroline only got confused. Piotr has his system, I have mine."
Wozniacki has yet to win a Grand Slam.