Justin Bieber and Jaden smith in Karate Kid

Teen phenom Justin Bieber and actor Jaden Smith (son of Hollywood A-listers Will and Jada) have joined forces for the theme song for the new “Karate Kid," in which Smith reprises the role made famous by Ralph Macchio in 1984.

"Never Say Never," is a "hip-hop flavored" offering, according to MTV.com. The lyrics are pure pump-up, as Justin croons go-get-'em lines like "I will never say never/I will fight till forever."

Smith, who comes in during the track's bridge, takes a page out of Eminem's book and sets up an epic confrontation through his rhymes.

"I can handle him/hold up/I can handle him/now he's bigger than me/taller than me/and he's older and stronger than me," says the boy wonder, who raps an awful lot like his dad.

Justin recently tweeted a message to his fans on Monday in the spirit of the song: "NeverSayNever to believing in your dreams ... u all make mine come true everyday. thank u :)."

"The Karate Kid," also starring Jackie Chan as kung-fu master Mr. Han (Mr. Miyagi in the original), is scoring some solid early reviews.