The hilarious pals did not disappoint on the Dec. 21 episode of Saturday Night Live, beginning the show with a hysterical sketch centered around wrapping—and rapping about—presents.
The singer-songwriter dressed up as a roll of festive red paper, complete with Mickey Mouse style hands and large white feet, as he tried to raise money and best Aidy Bryant's fundraising efforts. The 39-year-old funnyman joined Timberlake as a large green gift bag and the duo belted out their own humorous versions, centered around gift wrap, of "Roll Out" by Ludacris, Run-D.M.C's "It's Tricky" and Gotye's "Somebody That I Used to Know."
The SNL alum gushed during his opening monologue that he had a lot to be thankful for this year, including the birth of his baby girl Winnie Rose and taking over as the new host of The Tonight Show.
"Unfortunately they can't be here," Fallon said. "Traffic is tough this time of year and all of them are currently stuck in the Lincoln tunnel."
But the show must go on, so cue Fallon impeccably singing like the rock stars in a rousing rendition of "Joy to the World."
"You know, thank you very much, you know, I used to be with John Lennon, sing along if you know the words," Fallon said doing his best Paul impersonation, as the legendary Beatle walked on stage.
When Fallon asked how the 71-year-old Englishman made it after being stuck in traffic, Paul did not miss a beat and declared "I took a Citibike."
The duo then sang a wonderful version of "Have Yourself a Merry Little Christmas."
Timberlake showed us all (again) that he can perfectly imitate Fallon, and he did so in a sketch which pitted CBS against NBC during a game of Celebrity Family Feud.
Fallon, who was Jim Parsons from The Big Bang Theory, joined Timberlake and host Steve Harvey (Kenan Thompson) at the podium.
"Jim Parsons! Jim Parsons! Are you kidding me, that is how it is done my man!" Timberlake quipped as he bopped around the stage with his over the top hand gestures. Fallon and Timberlake both had to look at the answer board, and away from each other, to try not to break character.
The question was what is something you to do be sexy.
With the CBS team, which was also comprised of Ashton Kutcher, Jon Cryer and Alyson Hannigan, unable to answer the question, NBC went for the steal. However, all hope was lost for Fallon keeping his cool when Timberlake tried to take the game.
"So many great answers, so great!" Timberlake said as Fallon ducked behind the podium, probably laughing uncontrollably. And who can blame him.
Because the number one answer, and the way for a man to be really sexy, is to "be Justin Timberlake."
The Barry Gibb Show was back, with Fallon as Barry and Timberlake as his brother Robin, clad in matching blush seventies style suits and coordinated dance moves. The duo then spoke with guests Megyn Kelly (Cecily Strong), Paul Ryan (Taran Killam) and Madonna, who dropped by for a short cameo.
Fallon and Timberlake closed out the sketch singing "Talkin' It Up" with Bee Gees star Barry Gibb.
Mayor Michael Bloomberg joined Fallon on "Weekend Update" to discuss their plans for the new year.
Timberlake took the stage twice, performing "Only When I Walk Away" and "Pair of Wings."
Saturday Night Live will return with a new episode on Jan. 18, featuring Drake as the host and musical guest.
What did you think of Fallon and Timberlake? Sound off in the comments!
(E! and Saturday Night Live are part of the NBCUniversal family.)