Denis Shapovalov defaulted in Washington D.C. for swearing at spectator

WATCH: Full video of the Denis Shapovalov incident in D.C. ⤴️

There is tennis taking place this week outside of the Olympic Games, which we were reminded of Friday night, when tennis abruptly stopped taking place.

Trailing Ben Shelton in the quarterfinals of the Mubadala Citi DC Open by a set and 6-3 in the second-set tiebreaker, Denis Shapovalov threw his racquet to the ground after putting a backhand into the net. What followed is somewhat unclear, but Shapovalov clearly says something to a fan in the stands. Novice lip-readers can discern that one of those words began with the letter "f."

A code violation for unsportsmanlike conduct was given, and an ATP supervisor was immediately called to the court.

"What do you mean, he's talking to me," implored Shapovalov to the chair umpire, in a discussion about what transpired between the Canadian and the fan. "I'm going to tell him off.

"Give me a code, but don't call the supervisor."

A lengthy discussion between Shapovalov, the chair umpire, Shelton and the supervisor ensued. The chair umpire told the supervisor that Shapovalov said a spectator provoked him, but that he didn't know what was said.

"I heard it," insisted Shelton.

Then the chair umpire communicated to the supervisor what Shapovalov said in return.

"I would let it go," said Paul Annacone on Tennis Channel during the broadcast, emphasizing the subjectivity of the call.

But the supervisor did not. Despite the juncture of the match, with Shapovalov down three match points, Shelton was given the match when the Canadian was defaulted.

"The rules are what they are," said TC's Brett Haber, "and it's a slippery slope if you let someone get away with it, how you control it the next time."

After speaking directly with the supervisor, the 25-year-old remained at the baseline, incredulous at the outcome.

Give me a code, but don't call the supervisor. Denis Shapovalov

Shapovalov was clearly displeased, and railed the supervisor on his way out—we'll see what that means in terms of a possible fine and/or suspension—while Shelton couldn't believe what happened himself. The American was practically apologetic for winning the way he did, and also had some words with the official.

This is not the first time Shapovalov has been defaulted from a match, though the situations couldn't have been more different. During the 2017 Davis Cup, Shapovalov fired a ball towards the stands after losing a point, but it inadvertently struck hit umpire Arnaud Gabas in the eye. The incident prompted a default; Gabas required a medical procedure.

"I let a lot of people down, including my country, Davis Cup teammates, supporters and fans," Shapovalov said later than year. "I knew I couldn't undo what happened, so the only thing left was to face my mistake and work on never letting this happen again. I stayed in touch with Arnaud to check on his recovery and he has been incredibly gracious and understanding.

"[I]t occurred to me again that the Davis Cup incident was probably the most maturing experience for me since turning pro."