Taylor Fritz was heckled by a rival coach during a training session at the Madrid Open ahead of his match against Casper Ruud.
The incident took place on Monday and was captured in a viral clip on social media
Marat Safin, who coaches Andrey Rublev, grabbed a racket and stood on the other side of the court as Fritz practiced his serves.
His first attempt was sent crashing into the net, prompting a sarcastic response from Safin.
“Oh my God,” he yelled in mock exasperation before Fritz hit a second serve long and past the service line.
Safin, known for his fiery personality during his playing days, shouted at the American: “Go to practice, man!”
He then appeared to storm off in mock frustration to the delight of the fans in attendance.