Stefanos Tsitsipas' first round upset loss is not the only reason the tennis world is turning their heads to his US Open match. The No. 8 seed lost to fellow 21-year-old but unranked Russian Andrey Rublev 6-4, 6-7 (7-5), 7-6 (9-7), 7-5, and during the loss he insulted chair umpire Damien Dumusois.

The Greek player lost the first set but was able to come back to win the second-set tiebreaker before things started to take a turn. He was handed a coaching violation and then lost the third set before experiencing cramps in his legs.

The chair umpire warned Tsitsipas he was taking too long during the changeover while trailing 4-5 in the fourth set. The 21-year-old was not happy with the suggestions and made it known he was going to do what he wanted regardless of what Dumusois said. "I have to change [articles of clothing], give me a warning, I don't care," Tsitsipas told Dumusois. "Do whatever you want."

Tsitsipas' comments then escalated with him saying to Dumusois, "You have something against me. You're French, probably. ... You're all weirdos."

Tsitsipas went on to lose to his unseeded opponent as Rublev finished out the match strong. Tsitsipas was not expected to make such an early exit from the tournament and despite Rublev taking time off due to injury, he proved why he is one of the up-and-coming stars in tennis.