"I really don't know how I got here," Fallon, 39, said during a sentimental opening monologue for his first night at the helm of the legendary show.
"I remember asking my parents to stay up late to watch Johnny Carson," said Fallon, whose mom and dad waved and blew kisses from the audience. "I can just think there's some kid asking their parents to stay up to watch me."
After introducing himself to the 240-person audience, the former SNL cast member and Late Show host, backed by his house band The Roots, gave a shout-out to wife Nancy Juvonen and infant daughter Winnie, who were backstage, before warning the audience, "I'll make fun of everybody on this show."
Fallon admitted he was feeling the pressure of the new role – "I'll be your host ... for now," he joked – but he quickly got some major reassurance.
When the comedian joked that a friend bet him he'd never make it to The Tonight Show, Robert DeNiro came through the curtain and handed him a $100 dollar bill, followed by a line of other A-listers including Tina Fey, Kim Kardashian, Lady Gaga, Sarah Jessica Parker, Seth Rogen, Lindsay Lohan, Mariah Carey, Joan Rivers, Tracey Morgan and Mike Tyson. Despite pretending to be naysayers, the queue of celebrity friends made for one impressive welcome wagon.
Another Hollywood heavyweight, Will Smith, christened the couch as Fallon's first guest – and dance partner. The two teamed up for a hilarious synchronized hip hop dance demonstration – including Fallon twerking – before Smith over-shared about his time backstage. "I was trying to get Jada pregnant," he joked.
"This is the first time The Tonight Show has broadcast from New York in over 40 years," Fallon told the audience. In celebration of the new location, musical guests U2 performed their new song "Invisible" on the roof of a building in Rockefeller Center with the beautiful New York City skyline at dusk as their backdrop.
"I just want to do well," Fallon told the audience earnestly. "If you guys let me stick around long enough, maybe I'll get the hang of it."
On Tuesday, guests Jerry Seinfeld, Kristen Wiig and Lady Gaga stop by.