Just in case you didn't know, Nick Kyrgios doesn't like Novak Djokovic.
The firebrand Australian star, who labelled himself the Dennis Rodman of world tennis earlier this week, proved his petty dislike of the Serbian world No.1 isn't limited to their own interactions.
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Ahead of the French Open, Djokovic registered an easy straight sets win over Argentinian world No.96 Federico Coria at the Belgrade II Open.
The normally ho-hum result barely attracted any attention, with Coria posing for a selfie with Djokovic on court after the match.
But this seemingly innocuous transgression attracted the attention of Kyrgios, who ripped into the unsuspecting Argentine after he posted the selfie with Djokovic.
The highly competitive Kyrgios, by his own admission not the most 'professional' player on the tour, took a swipe at Coria's own professionalism after his 6-1, 6-0 defeat.
“So you are taking a photo after he has literally burnt you off the court,” he wrote.
“Very very strange mentality to have. Joker one of the best for sure, cmon g losing a set 6-0 then asking for a photo? That ain’t it.”
Kyrgios also wrote "this guy is a 'professional'" in a separate comment.
The online sledging come as Kyrgios prepares to rejoin the ATP Tour, having sat out much of 2020 due to the coronavirus pandemic.
Kyrgios hasn't played since the Australian Open back in February, and is preparing to make his ATP return at the Mallorca Open in June, in anticipation of Wimbledon.
For his part, Coria was unashamed of his decision to take a photo with his childhood 'idol'.
“I hugged him, I told him ‘I love you’ and I thanked him for all what he did for tennis. I was like a kid who meets his idol," he said.
Novak Djokovic battles to make Belgrade final
Novak Djokovic has negotiated an unexpected second-set fightback from Andrej Martin to seal his place in the final of his home Belgrade Open.
The world No.1 looked well placed to cruise to victory after taking just 38 minutes to win the first set 6-1, but qualifier Martin hit back in the second to force a decider.
Djokovic swiftly regained composure, though, with a bagel settling the contest 6-1 4-6 6-0 in his favour, and he will now have the backing of his home crowd as he looks to clinch his third Belgrade Open title and warm up for the French Open in style.
"I'm super excited to play in front of a Serbian crowd. This is my home town," said Djokovic, who previously won at the event in 2009 and 2011.
"I'm always excited, but also nervous, coming out on the court and playing in front of my home crowd. It's a very unique feeling. You feel a lot of pressure and expectations. But I'm just happy to fight for a trophy.
"I thought I started and finished the match really well, so I'll try to take those positive feelings into tomorrow's final.
"I also had some let-downs in concentration towards the end of the second set, and I'll try to correct those mistakes for tomorrow."
Standing in the way of a second title of the season for 34-year-old Djokovic is another qualifier, Slovakian Alex Molcan, who came from behind to beat Federico Delbonis 4-6 6-4 6-4.
Meanwhile in Parma, Sebastian Korda beat sixth-seeded Tommy Paul in an all-American semifinal at the Emilia-Romagna Open to reach his second ATP final.
The 20-year-old Korda won 6-3 6-3 in 82 minutes to book a spot against Italian wildcard Marco Cecchinato, who recovered from a second-set setback to prevail over Jaume Munar of Spain 7-6 (7-2) 1-6 6-1 after more than two-and-a-half hours.
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