Novak Djokovic declined a post-match TV interview after winning in the fourth round of the Australian Open after an on-air personality from the local Australian broadcaster of the tournament made negative comments about him in front of Serbian fans.

The presenter at the center of Novak Djokovic’s decision to boycott on-court interviews at the Australian Open has apologized to the 24-time Grand Slam champion, saying that he “overstepped the mark.” Channel 9 presenter Tony Jones was overlooking a group of Serbian fans while recording a dispatch from Melbourne Park Friday night.

Tennis star Novak Djokovic refused to participate in a customary post-match interview after advancing to the quarterfinals in the Australian Open on Sunday, blaming the tournament’s official broadcaster after a presenter “decided to mock” Serbian fans.