WHAT WAS SHE THINKING! LIL MAMA PULLS A KANYE!

Kanye West wasn't the only stage crasher at Sunday night's 2009 MTV Video Music Awards.

Rapper Lil Mama jumped onstage during a number by Jay-Z and Alicia Keys towards the conclusion of the star-studded show, taking the performers by surprise.

Lil Mama, a judge on "America's Best Dance Crew," suddenly sidled up to Jay-Z near the end of "Empire State of Mind" and began dancing and bobbing her head as the rapper and Keys continued singing.

But the duo didn't miss a beat, ignoring Lil Mama even as she struck an awkward pose with them as the song ended.

The intrusion didn't create nearly as much of a stir as earlier in the night, when an allegedly alcohol-fueled West grabbed the microphone from country singer Taylor Swift as she accepted an award for Best Female Video.

Last night's stunts come a few months after rapper T-Pain also interrupted a Jay-Z performance at Summer Jam by jumping onstage uninvited.