South Korean rap star Psy's music video Gangnam Style on Saturday became the most watched item ever posted to YouTube with more than 800 million views, edging past Canadian teen star Justin Bieber's 2-year-old video for his song Baby.

The milestone was the latest pop culture victory for Psy, 34, a portly rap singer known for his slicked-back hair and comic dance style who has become one of the most unlikely global stars of 2012.

Psy succeeded with a video that generated countless parodies and became a media sensation. He gained more fame outside his native country than the more polished singers in South Korea's so-called K-Pop style who have sought to win international audiences.