Dance steps with Will Smith. A concert with U2 under a blood-red sky. Tributes from Robert DeNiro, Lindsay Lohan, Tina Fey, Stephen Colbert and Mike Tyson. Not bad for a first day on the job.

Rather than brag about the entire affair, Jimmy Fallon, clad in two-buttoned gray suit and black tie, approached his initial turn as host of NBC’s venerable “Tonight” show with humility during a taping on early Monday evening. He talked to the audience as if many hadn’t watched him during his slightly less than five-year tenure on “Late Night.” He pointed out his parents sitting in the studio audience. And he told Will Smith, the first guest in what NBC dubbed “Show #0001” he was mindful of his place in the program’s long history: “This is a big deal, and it’s a lot of pressure,” he said. “Do you have advice for me, how to handle the pressure?”

NBC is positioning Fallon as the good-natured yin to the raunchy-fun yang evidenced by Jimmy Kimmel over at ABC. Fallon plays kiddie-favorite games with his guests; Kimmel asks them to read mean tweets about themselves. Fallon asks Bruce Springsteen to write a satirical version of “Born To Run” poking fun at New Jersey Governor Chris Christie. Kimmel enlists Matt Damon to take part in a fictional hijacking of his program,  letting the actor take pot-shots at the host all the while.

As CBS’ David Letterman moves closer to what is expected to be retirement, Fallon and Kimmel, along with a passel of cable competitors, represent the third post-Carson generation of late-night and the skirmish for audience is NBC’s to lose. “Tonight” has dominated for the Peacock for most of its time on the air. Yet as the latenight audience continues to splinter around a dizzying array of options – from Jon Stewart to Arsenio Hall to Chelsea Handler to reruns of Guy Fieri on The Food Network – there’s no guarantee either NBC or ABC will be able to rule outright.

NBC kept Fallon’s debut under close wraps Monday, allowing a handful of reporters to view the taping of the program only after agreeing not to disclose any details until after 12 a.m. eastern, when the show, delayed half an hour due to NBC’s Olympics coverage, was set to launch.

Among ad buyers, the general view is that Fallon’s show will likely lose a little bit of its audience, while maintaining a slight edge over competitors. For NBC, said Brian Hughes, senior vice president of audience analysis at Interpublic Group’s Manga Global, Fallon’s show is likely cheaper to produce than Leno’s, which makes it a sounder bet as TV is beset by ratings erosion amidst new viewing choices.

Yet Fallon could still maintain a lead. “The ‘Tonight Show’ with Fallon will more than likely beat Letterman once it settles in, but it will be by a small margin. Certainly not as big as the margin Leno had this past year,” said Billie Gold, vice president and director of buying and programming research at Carat, a large media buying agency that counts General Motors among its clients.  “In truth, this will be a three late-night show ‘dog and pony’ race in terms of total viewership, with Fallon having the edge thanks to the ‘Tonight Show’ legacy.”

If any of this was on Fallon’s mind as he embarked on what could be a years-long tenure, it only showed a little. “I’m Jimmy Fallon and I’ll be your host…for now,” he quipped. He made certain to note his predecessors on the program – even naming Conan O’Brien (and Jay Leno twice).

And he showed signs of the new feel and pace of his ‘Tonight,’, which has come back to New York City after a decades-long run on the West Coast. Fallon’s show is colored in red-and-gold hues and wood tones. The studio is significantly smaller than Leno’s soundstage. The monologue is still topical, but it’s not all delivered like a stand-up routine. As he did Monday evening, Fallon is likely to incorporate topical bits into the show’s first segment. On his first program, he designated yearbook superlatives to various Olympic athletes, with New Zealand skeleton runner Ben Sandford being named “Most Likely To Play Jazz Flute.”

Fallon’s team has booked an eye-popping array of guests for the show’s first two weeks. On his first program, Fallon convinced Smith to come out for a demonstration of the evolution of rap dancing in addition to the usual conversation segment. And he got U2 to take to the top of 30 Rockefeller Center for a brief concert along as well as to play an acoustic number in the studio. But the most fun part of the evening may have been an early segment in which Fallon chastised an unnamed friend who had always voiced skepticism over whether the entertainer would ever hold forth on “Tonight.” That pal, Fallon told the audience, owed him $100. After that, a parade of celebrities, including Sarah Jessica Parker, Mariah Carey, Seth Rogen, Lady Gaga and former New York mayor Rudy Giuliani (as well as those mentioned above), turned up to cough up a C-note.

“My goal is just to make you laugh and put a smile on your face so that you go to sleep with a smile on your face and live a longer life,” said Fallon, during the monologue. “Isn’t that the whole goal of what we’re doing? To have fun?”

NBC might beg to differ. But there’s little doubt the new host will produce a lot of laughs in the process.