Rap superstar 50 Cent lives in awe of the success of his mentor Eminem and likens him to tennis champion Serena Williams.

Eminem has defied racial stereotype to conquer the hip-hop world, much like Williams, who became the first black player to win a grand slam tennis title in 40 years when she won the US Open in 1999.

50 Cent, whose real name is Curtis Jackson, says: "I think Em' is like Serena Williams, the tennis player.

"There's no particular gender or race which is supposed to be involved in things. It's universal. Music is universal.

"Em' happens to be one of the best writers I've ever come across. Not many people are as talented."