Novak Djokovic splits with coach Goran Ivanisevic

World No. 1 Novak Djokovic has ended his longtime partnership with coach Goran Ivanisevic.

Djokovic, 36, collected 12 of his record 24 Grand Slam singles titles during his six-year run with Ivanisevic, 52.

The surprising split comes about two weeks after a third-round loss to 123rd-ranked Luca Nardi at Indian Wells.

"Goran and I decided to stop working together a few days ago," Djokovic posted Wednesday on Instagram. "Our on court chemistry has had its ups and downs, but our friendship was always rock solid."

Djokovic did not provide a specific reason for the breakup.

Since Ivanisevic joined his team in 2018, Djokovic won four Australian Open and Wimbledon titles each and two French Open and U.S. Open titles each.

Ivanisevic won one Grand Slam title during his playing career, Wimbledon in 2001.