WATCH: Boo or 'siuuu'? Daniil Medvedev speaks to Jim Courier after his second-round win at the Australian Open.


When Nick Kyrgios slammed down an ace against Liam Broady during their Australian Open first-round clash, something strange happened.

Instead of the usual calls of “Aussie, Aussie, Aussie” that a homegrown player would expect to hear, a cacophony of boos rang out across John Cain Arena. Kyrgios and Broady were both visibly confused, along with commentators and fans following at home, until they figured it out.

The fans weren’t booing, they were saying “siuuu!” — a reference to soccer superstar Cristiano Ronaldo’s signature goal celebration. But what does Ronaldo have to do with the Australian Open, and what do players think of the chants that have taken over in Melbourne Park?

Kyrgios celebrated his first-round win by doing Ronaldo's signature move.

Kyrgios celebrated his first-round win by doing Ronaldo's signature move.

First of all, let’s clarify the spelling: it’s not “siuuu” but “sim”, which is the word for “yes” in Ronaldo’s native Portuguese. He’s been celebrating goals the same way since 2013, during his days as a Real Madrid player.

The celebration—crossing his arms, jumping and spinning while shouting “siuuu”—has been as synonymous with Ronaldo as his goals and records.

So it’s no surprise that Ronaldo’s celebration has crossed over into pop culture, as well. Similar to Daniil Medvedev’s instantly memorable “dead fish” celebration at the 2021 US Open, “siuuu” has been made even more popular thanks to featuring in FIFA video games and viral challenges.

As to why it has been heard shouted by tennis crowds at the Australian Open, that’s still a mystery—but it hasn’t stopped players from chiming in.

Here’s what some of them had to say:


Nick Kyrgios

During his match against Broady, Kyrgios leaned into the “siuuu” chants, going from confusion to amusement to egging on the crowd for more. The 26-year-old Aussie delighted fans by performing Ronaldo’s iconic celebration on court after the victory, and the chants have followed him during his doubles matches alongside Thanasi Kokkinakis.

“They actually weren’t saying ‘boo’. It’s just a stupid [chant],” Kyrgios said. “They were doing some Ronaldo thing. Ronaldo does it every time he scores.

“I thought they were going to do it for like 10 minutes—they did it for two and a half hours. Like every point, I don’t know why. It was a zoo out there.”

Andy Murray

Former World No.1 Andy Murray wasn’t a fan either, and at first, he too thought he was getting booed during his five-set win over Nikoloz Basilashvili.

“After a few times it was like, no, [they’re not booing] they’re doing that, I think it’s like ‘siuuu’ or something, that Ronaldo does when he scores,” Murray said. “It was incredibly irritating.”

Medvedev wrote "siuuu" on the camera lens after defeating Kyrgios.

Medvedev wrote "siuuu" on the camera lens after defeating Kyrgios.


Daniil Medvedev

US Open champion Medvedev knew that he would be up against a partisan crowd when he faced Kyrgios in the second round, so he was probably expecting to be heckled. But hearing “siuuu” after every point, even in between first and second serves, wore on the frustrated Russian.

"Those who are doing it probably have a low IQ," Medvedev later told Eurosport.

But even still, Medvedev departed the court by cheekily signing “siuuu” on the camera lens after his 7-6(1), 6-4, 4-6, 6-2 win.

“I was like, Well, okay, I'm going to write it then because everybody is doing it. So I guess that's the thing to do,” Medvedev said.

He added: “Probably if you look at it on the TV — I'm probably not going to do it tonight, but maybe after the tournament— I'm going to be, like, ‘Wow, that's a great atmosphere for a tennis match.”

High-energy crowds are always great for tennis, and it's no different at the 50-percent capacity Australian Open. But when players think they're being booed constantly, maybe it's time to retire the "siuuu" and bring back the old "Aussie, Aussie, Aussie" instead.