Conan O'Brien's 'Tonight Show' debut scores highest Monday in four years

Conan O'Brien's premiere as host of NBC's "Tonight Show" drew the highest overnight ratings for a Monday episode in four years.

Launching his "Tonight Show" run, the late-night comedian posted a number 82% higher than the "Tonight" second quarter average and 173% above his February "Late Night" finale.

O'Brien averaged a 7.1 rating and 17 share in metered-market households, "Tonight's" strongest Monday overnight results since a 2005 telecast featuring a tribute to Johnny Carson.

O'Brien won his time period by a 154% over CBS's "Late  Show with David Letterman" (2.8/7). His success spilled over to the rest of NBC's late-night lineup. "Late Night with Jimmy Fallon" (2.5/9) delivered its highest overnight rating yet for a Monday telecast, topping the show's series premiere. 

Reviews were generally positive:

-- Time: "He's come a long way from the nervous comedy writer he was then. The guy we saw on the Tonight Show stage was polished, off-the-cuff funny, dapper, poised—but not, substantively, all that different from the Conan of Late Night."

-- Hollywood Reporter: "After one show, let's say he's a work in progress"

-- USA Today: "All in all, O'Brien got his Tonight off to a decent start, though you still got the sense you were watching an introduction more than a settled production. But that's fine: The goal right now is just to put O'Brien's name on the show."

-- Chicago Tribune: "He seemed a little nervous during the opening monologue and ever so slightly tense during his interview with his first guest, Will Ferrell, but those are normal opening-night jitters, and through it all, Conan still appeared to be enjoying himself. Given a few weeks to ease into the job, Conan's "Tonight" show should go over fine with Middle America."

-- Variety: Clever, but more misses than hits.

Some clips...

UPDATE: Conan's second "Tonight Show" episode drops 30% in ratings