South Korean pop sensation Psy's "Gangnam Style" on Saturday became YouTube's most-watched video of all time, registering more than 803 million views to overtake "Baby" by Canadian heartthrob Justin Bieber.

The 34-year-old rapper has rocketed to fame since his "Gangnam Style" video - in which he performs his now famous horse-riding dance - became a worldwide hit following its release in July.