|Actor Will Smith joins Jimmy Fallon on his debut on The Tonight Show as host since Jay Leno's departure. |
Trailing well behind were CBS's The Late Show with David Letterman and ABC's Jimmy Kimmel Live, each with 5 per cent of households tuned in.
Leno, 63, signed off from The Tonight Show after 22 years on February 6 as NBC relocated the show from Los Angeles to New York and put Fallon, 39, in the host's chair in a bid to attract a younger, hipper demographic.
"I really don't know how I got here," said Fallon to a cheering studio audience after passing through a blue curtain to take the reins of one of the greatest franchises in American television.
"I just want to do the best I can, and take care of the show for a while," he added.
"If you guys let me stick around long enough, maybe I'll get the hang of it."
His guests on Monday night's show included Will Smith and U2, the latter performing atop Rockefeller Center, plus a parade of other celebrities including Lady Gaga, Lindsay Lohan, Mike Tyson, and Robert De Niro who paid back mock $US100 bets that Fallon would never host the show.