I'll be your host ... for now.
So opened Jimmy Fallon as host of The Tonight Show on Monday, as the former SNL cast member took over for Jay Leno and welcomed a star-studded lineup on his first night.
Robert DeNiro cam out to pay up on a $100 bet during the monologue - and that was just the beginning.
Others who stopped by included Tina Fey, Kim Kardashian, Lady Gaga, Sarah Jessica Parker, Seth Rogan, Lindsay Lohan, Mariah Carey, Joan Rivers, Tracey Morgan and Mike Tyson.
1. Kim Kardashian on The Tonight Show
Kim Kardashian was among the many celebrities who stopped by Jimmy Fallon's Tonight Show debut. She owed him some money.
2. Mike Tyson on The Tonight Show
Here, Jimmy Fallon! Mike Tyson settles a bet during this Tonight Show cameo.
3. Lindsay Lohan on The Tonight Show
Lindsay Lohan stopped by The Tonight Show with Jimmy Fallon. She was one of many big names to show up for his premiere.
4. Stephen Colbert on The Tonight Show
Stephen Colbert snaps a selfie with Jimmy Fallon on the latter's debut as Tonight Show host.
5. Joan Rivers on The Tonight Show
Joan Rivers stops by the first Tonight Show under the guidance of Jimmy Fallon in this photo.
7. Tracy Morgan on The Tonight Show
Tracy Morgan settles a bet here with Jimmy Fallon. He was wrong about the comedian never hosting The Tonight Show.
8. Sarah Jessica Parker on The Tonight Show
Sarah Jessica Parker paid Jimmy Fallon $100 because she lost a bet with the new Tonight Show host.
9. Seth Rogen on The Tonight Show
Seth Rogen made a fun cameo on Jimmy Fallon's first episode as host of The Tonight Show.
Will Smith was the first official guest, pre-taping a segment titled "The Evolution of Hip-Hop Dancing" and then talking about such topics as skydiving and snowboarding.
U2 played as the musical guest and, overall, Fallon came across as both nervous and sincere.
"I just want to do well," Fallon told the audience . "If you guys let me stick around long enough, maybe I'll get the hang of it."
What did you think of Fallon's debut? Grade it now: