CNN  — 

Daniil Medvedev described some of the Australian Open crowd as having a “low IQ” following his four-set win over home favorite Nick Kyrgios.

Medvedev was given a stern test by Kyrgios, eventually winning 7-6 6-4 4-6 6-2, in front of the partisan home support and the Russian was frustrated by the crowd after mistaking cries of Cristiano Ronaldo’s ‘Siu’ celebration with boos.

“When you get booed between first and second serve, it’s not easy, so you just have to stay calm and win the match,” he told Jim Courier in his on court interview.

Courier, a former Australian Open champion, tried to explain that the crowd was shouting ‘Siu’ instead of booing. “It’s a soccer thing, a football thing,” he said.

Medvedev replied by telling the crowd he couldn’t hear what Courier was saying, imploring the crowd to “show some respect for Jim Courier.”

“If you respect somebody, at least respect Jim Courier,” he said.

Courier got closer to Medvedev and again explained that “they’ve been saying is ‘Siu,’ which is a thing, I think, they say when Ronaldo scores a goal.”

READ: Cristiano Ronaldo’s ‘Siu’ celebration causes confusion at the Australian Open

Daniil Medvedev mistook shouts of 'Siu' with boos.

“I don’t think they’re booing you,” he said. “I hope I’m right on that one.”

Despite Courier’s explanation, Medvedev was clearly still unhappy in another post-match interview.

“It’s not anger, it’s just a little bit disappointing,” he told Eurosport. “I guess it’s normal that everybody experiences it, especially when you play a home favorite and not just a home favorite, but Nick.”

“I had a few moments on my serve – many games were actually quite easy for me, a lot of aces – were tough and he managed to make some good returns, then I have a break point on [my] second serve and people are cheering like you already made a double fault.

“I mean, that’s just disappointing because it’s not everybody that’s doing it, but those who are doing it probably have a low IQ.”

So far, the crowd at this year’s Australian Open has taken every opportunity to mimic Ronaldo’s celebration in the stands, which has led to some confusion.

Nick Kyrgios performed the 'Siu' celebration after winning his opening round match.

During the opening round, multiple news outlets, commentators and even some players mistook the shouts of ‘Siu’ for boos, before eventually realizing what fans were actually shouting.

The chants have received mixed reviews from players, with Kyrgios unsurprisingly relishing the boisterous support. After his opening round win over Liam Broady, the 26-year-old performed the ‘Siu’ celebration on court – much to the delight of the fans.

However, it’s fair to say Andy Murray wasn’t quite as into it.

“It’s painful stuff that,” the three-time grand slam winner said during his on-court interview as the sounds of ‘Siu’ echoed around the stands.

“I think it’s like ‘Siu’ or something, what Ronaldo does when he scores,” he added in his post-match press conference. “It was incredibly irritating.”