The video: Yep, they did it again. The last time Justin Timberlake stopped by Jimmy Fallon's late-night talk show, in September 2010, the duo delighted audiences and launched a viral sensation with their performance of "The History of Rap," a winking medley of hip-hop's greatest hits, from the Sugarhill Gang to Soulja Boy. "It was perhaps one of the greatest late-night clips of the decade," says Linda Holmes at NPR. On Tuesday, while Timberlake was on Fallon's show plugging his new film Friends With Benefits, the two unleashed a 5-minute sequel, "The History of Rap, Part 2." (Watch the video below.) The "marvelous medley" featured nearly two dozen hip-hop standards, including Public Enemy's "Bring the Noise," Salt n' Pepa's "Push It," and a "particularly charming" sing-a-long finale of Biz Markie's "Just a Friend."

The reaction: "Ladies and gentlemen, prepare yourselves to be wowed once again," says Mike Hess at Celebuzz. The duo impressively tackled tricky tracks like "Insane in the Brain," "Hey Ya," and "It Takes Two," says Gil Kaufman at MTV. "The music just flows seamlessly." If anything, says the Cleveland Plain Dealer, the clip proves that the two performers have serious chops. There's no doubt that Fallon is more than "just a lucky comedian," and Timberlake has solidified his status as "an all-around entertainer," one with "charisma, talent, and a complete absence of fear." Check it out for yourself: