Letterman beats NBC's 'Tonight Show'

David Letterman overtook Conan O'Brien in the household ratings Tuesday night.

CBS "Late Show" earned a higher overnight number than NBC's "Tonight Show" for the first time since the NBC late-night franchise switched hosts from Jay Leno to Conan O'Brien last week.

Marking the seventh day of Letterman vs. O'Brien, CBS earned a 3.4 metered-market household rating to NBC's 2.9. "Late Show" was also up 13% from last week and 17% from last year.

Letterman had Julia Roberts and Black Eyed Peas as guests; O'Brien had Eddie Murphy, Angela Kinsey and Bonnie Raitt.

The ratings gap between the hosts has been narrowing nearly every night since O'Brien took control of "Tonight." The last time "Late Show" topped "Tonight" under Jay Leno was eight months ago.

One mitigating factor: NBC aired live NHL playoff coverage Tuesday in primetime, which led to low-rated local programming airing in the latter hours on the West Coast, potentially providing "Tonight" with a weaker-than-usual lead-in.

When asked about O'Brien's ratings yesterday at an event, NBC co-chair Marc Graboff noted that the late-night ratings game "is a marathon," not a sprint, and that this is a contest that will be fought over years.

Also, Graboff said the network is focusing on the adult demo ratings in this race, the numbers for which have not yet been released by Nielsen. O'Brien attracts a younger audience than Letterman, and when those 18-49 figures become available tomorrow, NBC expects they will tell a different story than the overnights, which measure overall household viewership.

Still, NBC would rather not lose this hour in any major measurement category after having easily ruled the time period for years.

UPDATED: In primetime, ABC won Tuesday with Game 3 of the NBA Finals (14.2 million viewers and 5.9 adults 18-49 rating), followed by NBC with Game 6 of the NHL Stanley Cup Finals (5.8 million, 2.4), CBS with repeats and Fox with a repeat and "Mental" (4.7 million viewers, 1.4).

Here's a chart of "Tonight Show with Conan O'Brien" ratings so far:

 

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