Taylor Fritz kept his cool in the face of an irate Daniil Medvedev to win the opening match of the ATP Finals in straight sets.
American Fritz recorded his 50th win of the year by beating Medvedev 6-4 6-3 at the season-ending tournament in Turin, Italy.
Russian fourth seed Medvedev broke a racquet in response to his poor serving and threw a second after a stroke of bad luck while break point down.
"I'm super happy with how I played today," said Fritz, who reached his first Grand Slam final at September's US Open.