Cristiano Ronaldo first popularised the Siu celebration while at Real Madrid, explaining that it came from 'sí', the Spanish word for yes, shouted by fans and teammates. His routine combines a leap, a mid-air turn and arms thrown wide on landing, with the word stretched as he lands. Clips from matches spread widely on YouTube, TikTok and football fan pages during his time at Real Madrid, Juventus and Manchester United, turning the shout into a universal victory chant copied by players, fans and meme editors worldwide.