"It cost me the f***ing set. Bulls***!" - Nick Kyrgios after controversial umpiring call during Toronto 1r loss to Reilly Opelka

Tennis' wild child Nick Kyrgios went off the rails yet again in his first-round encounter against Reilly Opelka at the 2021 National Bank Open on Monday. The Aussie got into a heated argument with the umpire following a judgment call late in the second-set tiebreaker, and ended up losing the match in three sets.

Kyrgios had gotten off to a good start, as he took the opening set 6-4 on the back of some impeccable serving. But Opelka refused to go down quietly, staying strong on his serve to force a tiebreaker in the second set - which is where it all went down.

At 4-4 in the tiebreaker, Opelka blasted a huge serve out wide, eliciting a weak return from Kyrgios. However, the Aussie's shot had a little back-spin on it, which led to the ball swerving towards his side of the court after bouncing.

Not to be deterred, Opelka made a quick last-ditch effort to reach the ball. But he ended up getting extremely close to the net before swatting away the winner.

Kyrgios immediately pointed towards Opelka, expecting the umpire to dock him a point for touching the net with his foot. The umpire, however, refused to call it since she hadn't seen the American making contact with the net.

Here's the full exchange between Nick Kyrgios and the umpire at that stage of the match:

Nick Kyrgios: "What are you watching? I can see it from a foot away, I saw his foot touch the net."

Umpire: "I’m not going to call it if I don’t see it."

Nick Kyrgios: "What are you watching, bro? I can see his foot touch the net from where I am, and you don’t call anything. It’s a joke, bro. It cost me the f***ing set. Bulls***!"

The entire point as well as parts of the conversation can be seen in the highlights video below, at the 1:30 mark.

Also, here are a couple of slow-motion GIFs of the incident from different angles:

Another angle shown in the highlights. No conclusive evidence that Opelka touched. #NBO21 #Kyrgios pic.twitter.com/kHygBBbGWt

— Tennis GIFs 🎾🎥 (@tennis_gifs) August 10, 2021

Nick Kyrgios subsequently double-faulted on set point at 4-6, gifting the second set to Reilly Opelka. The Aussie followed that up by smashing a ball into the stands, still looking very annoyed by the umpire's call.

Opelka took control of the match from that point onwards, and broke Kyrgios in the third game of the decider. The American went on to complete a 4-6, 7-6 (4), 6-4 victory and move into the second round in Toronto.

What do the rules say about the controverisal call during the match between Nick Kyrgios and Reilly Opelka?

Although Nick Kyrgios believes the umpire failed to use her discretionary powers properly, a closer look into the ITF rule-book suggests that she was right to not penalize Reilly Opelka.

According to Rule 24 (g) & (h), a player is to be docked the point in the following cases:

"The player or the racket, whether in the player's hand or not, or anything which the player is wearing or carrying touches the net, net posts/singles sticks, cord or metal cable, strap or band, or the opponent's court at any time while the ball is in play, or;"

"The player hits the ball before it has passed the net."

Reilly Opelka was clearly not in violation of either rule. The umpire didn't see Opelka touch the net with her own eyes, and the American also seemingly made contact with the ball just as it was trailing away from his side of the court. That means the aforementioned rules couldn't be implemented in his case.

Some fans on Twitter have claimed that Opelka putting his racket on a ball which was on Kyrgios' side of the court warranted a violation. However, that is not the case either; according to Rule 25 (b), the return is good if:

"After the ball in play has hit the ground within the correct court and has spun or been blown back over the net, the player reaches over the net and plays the ball into the correct court, provided that the player does not break Rule 24."

If Nick Kyrgios had been fully aware of the rule at the time, he might have held back on his anger. But as it turned out Kyrgios couldn't keep his composure, and the result is that Reilly Opelka is in the Toronto second round and the Aussie isn't.