David Letterman Tops Jay Leno in Adult Demos

UPDATED: Three weeks into the season, the "Late Show" claims a close ratings victory over the "Tonight Show."

Three weeks into the new season, David Letterman has topped Jay Leno in the ratings.

For the week of Oct. 3-7, CBS' Late Show With David Letterman topped NBC's Tonight Show With Jay Leno in the coveted 18-49 demo, posting a 0.9 rating versus a 0.8 for the latter. Up until then, both late-night talkers had tied; both posted a 0.8 during the week of Sept. 19-23 and a 0.9 during Sept. 26-30.

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The Late Show also topped Tonight Show among adults 18-34 (0.6 vs. 0.5). Both posted a 1.2 in the older 25-54 demo.

Even with Letterman taking home a close victory for last week, the Tonight Show still outdrew Late Show in overall total viewers, drawing 3.6 million versus 3.3 million. NBC touts this lead as the Tonight Show's biggest over the Late Show during the third week of a season since 2008.

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As the competition between Letterman and Leno continues to heighten, ABC News' late-night program Nightline is outdrawing Late Show and Tonight Show in total viewers (3.9 million), 18-49 (0.9, 1.18 million) and 25-54 (1.3, 1.6 million).

NBC's Late Night With Jimmy Fallon outdrew CBS' Late Late Show With Craig Ferguson in viewership (1.7 million vs. 1.5 million), but both shows tied in the 18-49 demo with a 0.5.