Juventus forward Cristiano Ronaldo has revealed the origin of his famous goal celebration, tracing its emergence to the goal he scored against Chelsea in the United States in 2013 while playing for Real Madrid in a pre-season match.

The 34-year-old scored twice and set up the opener as his former club, Real Madrid, defeated Chelsea 3-1 in the final of the Guinness International Champions Cup.

“Well I was in the US and we played against Chelsea and I don’t know where it came from. I just scored and I went, ‘siuuuu!’”, Ronaldo said on YouTube channel Soccer.com.

“But it was natural, to be honest. After that I started doing it and I feel like the fans, when they see me they’re like ‘siuuuu’ and I was like, ‘wow, people remember Cristiano because of the siuuuu,’ so I continued like that.

In that particular match, with scores level in the 30th minute, Ronaldo was the recipient of a hard tackle from behind by Branislav Ivanovic. Ronaldo merely smiled as he sat on the turf, adjusting his kit while most of the other players convened for a bit of shouting.

Ronaldo got his revenge on the resulting free kick. From about 25 yards, his strike curled to the left, sneaking just under the crossbar and off the fingertips of the diving Cech. And his famous “siuuuu” celebration started.

The Portuguese scored again in the 57th minute, perfectly timing his run toward the goal line and steering in a header to complete the scoring.