Kyrgios, 24, is a volatile sort who repeatedly has gotten in trouble for on-court actions, including getting kicked out of the Italian Open in May after throwing a chair and being suspended by the ATP in 2016 for not trying to win and insulting fans during the Shanghai Masters.

Earlier this month, Kyrgios, currently ranked 27th, won the Citi Open in Washington and said he had turned a page in his professional and personal lives.

In the last match on center court Wednesday night, he was back to his old form. During a changeover in the second set, he yelled from his chair: “The worst ref in the game, hands down.” He then vulgarly insisted the umpire does something “stupid” every time he plays.

Early in the third set, Kyrgios took two rackets to the tunnel that leads to the locker room, smashed them on the ground and returned to the court. Warned that he needed to get ready to return Khachanov’s serve, he took a new racket to the baseline and stood taping the handle instead of getting in position to play.