Willow Smith Dougies with Justin Bieber

Willow Smith went from the schoolyard to the Staples Center, making a surprise appearance during Justin Bieber’s sold-out show last night in Los Angeles. The teen heartthrob brought the youngest Smith out to perform “Whip My Hair” before the singing sensations taught the crowd how to Dougie. Willow’s brother Jaden and Usher also joined the Biebs earlier in the evening.

“LA TONIGHT WAS CRAZY!!!! USHER, JADEN, SEAN, and even my lil sis WILLOW SMITH!!!! WE SHUT LA DOWN!!!!!!!! LOVE YALL” tweeted Bieber.

Log on to chat with Willow, whose single has already cracked the top 25 songs on iTunes, in her first Ustream session tonight at 7:30 p.m. EST.