His first Nielsen Media Research report card shows a 7.1 rating and 17 audience share in the nation's biggest media markets. The numbers indicate more people checked out O'Brien's show out than watched David Letterman's "Late Show" and ABC's "Nightline" combined.
A typical "Tonight" show this season had a 4.0 rating. Each ratings point represents 1 percent of the nation's homes with TV, which means 7 percent of homes had someone watching O'Brien on NBC.
Monday, O'Brien joined a line of predecessors - - Steve Allen, Jack Paar, Johnny Carson and Jay Leno - - on television's most historic late-night franchise.
"I think I've timed this move perfectly," he said in his opening monologue aired Monday night. "I'm on a last-place network, I moved to a state that's bankrupt and 'The Tonight Show' is sponsored by General Motors."
O'Brien spent 17 years as host of NBC's "Late Night" in New York, and the move up one hour has been in the works for five years. Leno, his immediate predecessor, will do a weeknight prime-time show on NBC. The workaholic Leno will start "in two days, three days tops," O'Brien joked. Actually, it's in September.
O'Brien christened a new studio on the Universal City lot with a handsome art-deco look. The stage has a blue glass background for the opening monologue, before O'Brien retreats to a desk in front of a sparkling backdrop of Los Angeles.
From the top, O'Brien showed the silly comic style that sets him apart from Leno, with more comedy skits filmed earlier and less reliance on jokes in front of the studio audience. The first one showed O'Brien marking off a to-do list for his new show. "Move to L.A." was the last item, as a camera panned a New York skyline outside his window.
A frantic O'Brien went out in the street to find a cab. When he couldn't, he began running. He ran out of New York, and sprinted across the country - across Wrigley Field in Chicago, past the Gateway Arch in St. Louis, by the Rockies and through the desert to Las Vegas. Finally he arrived at the locked door to his new studio, only to realize he'd left his keys behind.
In other segments, O'Brien commandeered a tram filled with tourists on a Universal Studios lot tour and took his used green Ford Taurus for a ride into Los Angeles' car-obsessed culture. Fabio complimented him on his ride.
O'Brien appeared nervous at the long-awaited opening night, pacing onstage during his monologue and mugging with his red pompadour.
"I remember watching Johnny Carson when I was a kid and thinking: That's what I want to be when I grow up," O'Brien said. "I'm sure right now in America there is likely a kid watching me, thinking: 'What is wrong with that man's hair?"'
Longtime sidekick Andy Richter slid smoothly into the role Ed McMahon once played for Carson, standing at a podium to the side of the stage and loudly laughing at his boss' jokes.
Over at CBS, David Letterman slyly mentioned NBC's transition.
"I'm still here," he said. "I knocked off another competitor."
He said he got a call from his mom and she said, "Well, David, I see you didn't get 'The Tonight Show' again," a reference to Letterman losing out to Leno to become Carson's successor.
Comic Will Ferrell was O'Brien's first guest, his appearance less manic than some of his memorable "Late Night" visits. He offered O'Brien some "tips" for L.A. living, including a good burger joint in Pasadena "called Burger King."
Pearl Jam was the musical guest, debuting a song off an upcoming album.
Ferrell sang his own song in tribute to O'Brien, a version of "Never Can Say Goodbye" that "bewildered" the host. Why sing a goodbye song on the first night?
"Don't get me wrong," Ferrell said. "I'm pulling for you. But this little thing is a crapshoot at best."