Not many people could upstage Jay-Z and Rihanna, but Beyoncé's nephew Julez did just that at Sunday night's (January 31) Grammy Awards.

Solange Knowles' son offered a tepid "No thanks" when Rihanna offered him the microphone at the awards show. The 5-year-old was onstage with Rihanna and Jay after their hit "Run This Town" scored a Grammy win for Best Rap/Sung Collaboration. Dressed in a dapper tuxedo, Julez delighted the crowd when he was invited to accept the award by his Uncle Hov.

The latest star from the Knowles' clan, Julez was born Daniel Julez Smith Jr. in 2004. He was named after Solange's ex-husband, Daniel Smith, whom the singer married the same year. Julez's first uncredited appearance came courtesy of Destiny's Child when Solange showed off her very pregnant belly in the group's "Soldier" video. He was also the subject of a song on Solange's 2008 album Sol-Angel and the Hadley St. Dreams titled "An Ode to Julez."

Julez proved to be a cool customer at the Grammy Awards. First, Jay-Z thanked the crowd for his win before he passed the mic off to Rihanna. The singer offered her quick words and turned to Julez. Rihanna picked up the tiny Knowles as she asked him if he had anything he wanted to say. "No thanks," he said sheepishly, drawing laughter from the audience.

His tight-lipped answer earned him a burst of fame and a tweet from his mom, who passed on the festivities. "Julez is going to enjoy seeing that when he's 13," Solange wrote, followed by a smiley-face.

The 2010 Grammy Awards may be over, but MTV News will have much, much more from the show, including reports on your favorite nominees, party photos, behind-the-scenes video and much more from the big show!