Nothing like a good ole' dance off to kick off a birthday party! Justin Bieber and Diddy went toe-to-toe in a dance off during Usher's surprise star-studded birthday bash at Bootsy Bellows on Monday, Oct. 14. The "Yeah" singer celebrated turning 35 alongside some of his famous pals at the West Hollywood club including Blake Shelton, T.I. and Jermaine Dupri, a source reveals to Us Weekly. The appearance by his former Voice pal Shelton "was a huge hit." Miguel and Sugar Ray Leonard were also in attendance.
"Usher was completely surprised. Guests arrived at 10:30 p.m. and Usher came at 11," a source told Us. "Bieber came with Scooter [Braun] and hung out with Usher in a booth. Usher's girlfriend Grace [Miguel] was there as well."
The S&M Cirque du Soleil themed party had girls "in plastic balls and with whips and chains." Guests also enjoyed a cake made to look like a boxing ring. (Usher is set to play the retired professional boxer Leonard in the 2014 film "Hands of Stone.") "Usher was clearly having the time of his life," the insider added.
DJ Rashida entertained the guests, and eventually Diddy and the "Heartbreaker" singer took it to the dance floor at 1 a.m. to "All I Want For My Birthday" by 2 Chainz -- including the birthday boy! "All the guys were dancing and there was sort of a dance-off between Usher, his one-time protege Bieber, Diddy and the others," the eyewitness said. "The crowd was going nuts." The "Boyfriend" singer clearly had a good time too. After the party, he tweeted: @Usher that was a great time. love u man. happy birthday."
Keep clicking to see lots more birthday bash photos from Usher's Instagram ...