We already know Justin Timberlake can do funny on "Saturday Night Live," and serious in "The Social Network." He can obviously sing (though he doesn't seem that interested in doing it lately), and now he's top-lining his first motion picture with "Friends With Benefits."

But the dude can also rap, which he proved again on Tuesday night when he visited old pal Jimmy Fallon on "Late Night With Jimmy Fallon" and dropped a blazing sequel to their first road trip through hip-hop with an equally head-spinning "History of Rap 2."

Though he made it seem like he was once again reluctant to pick up the mic, it took very little convincing to get Timberlake to lace up. "No, no, no stop. It's not gonna happen, we can't do it again, we can't top ..." Timberlake told the cheering crowd before locking eyes with Fallon and grabbing a conveniently hidden microphone from behind his chair and strutting to the stage.

Over the next five minutes, he and Fallon ripped through two dozen classics, opening with Kurtis Blow's legendary "The Breaks," before segueing into another early rap totem, Grandmaster Flash and the Furious Five's "The Message," complete with both men busting out their best robot dance moves.

It's easy to sound great when you've got the Roots backing you up, and the band was more than up to the task, hitting the right bass-heavy tone for N.W.A.'s "Express Yourself," as Fallon and Timberlake traded off on a verse, then nimbly pivoting into a peek at Public Enemy's "Bring the Noise." Curiously, it was Fallon who did most of the heavy vocal lifting, taking on the chorus to Rob Base and DJ EZ Rock's "It Takes Two" as Timberlake jived behind him and added the song's indelible yelps.

From there they busted through a variety of hip-pop standards: Salt n' Pepa's pelvic-thrusting "Push It," a tiny taste of Vanilla Ice's "Ice Ice Baby," Black Sheep's "The Choice Is Yours," Cypress Hills' "Insane in the Brain" and a hip-swiveling throwdown of DJ Kool's party anthem, "Let Me Clear My Throat." The pair had clearly rehearsed the bit to a T, because neither stumbled even for a moment during the routine. Whether it was their thuggish ruggish take on DMX's thudding "Up in Here," Timberlake's swishing falsetto break on Nelly's "Hot in Herre" (which lead to an awkward moment where both men seemed to question their sexuality for a brief second), or their intertwined duet on 50 Cent's "In da Club," the music just flowed seamlessly.

Timberlake gave the crowd a bit of sugar during Outkast's "Hey Ya," shaking his booty while Fallon sang the verse, before both men took on the falsetto chorus. They then teased Lil Wayne's "A Milli" and got their Auto-Tune on for DJ Khaled's "All I Do Is Win."

While Fallon needs a bit of work, clearly nobody has to school Timberlake in the finer art of Cali Swag District's "Teach Me How to Dougie," though the former boy-band star did have to ease his co-star back a bit when Jimmy got a tad too into character and in the cameraman's face during a menacing trip through Rick Ross' "Blowing Money Fast."

"Jimmy, Jimmy, stop ... why do you always do that?" a concerned Timberlake said as he pulled his pal back.

The whole shebang ended with the boys trading lines on Biz Markie's "Just a Friend" and then rolling out into the studio and getting the audience to help them sing the chorus. "Clap your hands, everybody, if you got what it takes, cuz I'm Justin, I'm Jimmy and we want you to know that these are the breaks," they chanted as they brought it all home.