Australian Nick Kyrgios was involved in a prolonged argument with French umpire Damien Dumusois during his first-round exit at the Shanghai Masters.
The 23-year-old world number 38 was beaten 4-6 6-4 6-3 by American qualifier Bradley Klahn, ranked 104.
Dumusois told Kyrgios a point in the second set was "really borderline," appearing to suggest a lack of effort.
Kyrgios reacted by saying "I don't care" and told Dumusois "you have no right to tell me that it's poor".
He later sarcastically asked Dumusois "was that borderline?" after serving an ace.
Kyrgios lost five straight games from 4-4 in the second set in a match that lasted one hour and 17 minutes.