Kanye West throws jab at Ray J during Late Night TV performance

Kanye West has taken aim at his girlfriend Kim Kardashian's ex Ray J by branding him "lame" and questioning his manhood during a surprise TV performance on Monday night (09Sep13).

The Stronger hitmaker made an unannounced appearance on Late Night with Jimmy Fallon to play his new single Bound 2 with music veteran Charlie Wilson, and he used his stage time to take a subtle jab at Ray J at the top of the song.

However, West stopped short of mentioning the One Wish singer by name - instead, he namechecked Ray J's only sibling, R&B star Brandy, to make it clear to fans who he was referring to.

Before launching into his first verse on Bound 2, West unveiled a new line, spitting, "Brandy's little sister lame, man, he know it now".

West and Wilson were backed onstage by presenter Jimmy Fallon's house band, hip-hop group The Roots, and in a subsequent post on Twitter.com, drummer Questlove revealed the rapper simply called him and asked to perform after touching down in New York, where the show is filmed.