Letterman can’t hang on to No. 1

The glow from David Letterman’s return after a monthlong absence was fleeting.

Although Letterman’s “Late Show” edged “The Tonight Show With Jay Leno” on March 31 -- the host’s first night back after a layoff caused by shingles -- complete ratings for the week ending April 4 show Leno averaging 5.4 million viewers to 4.1 million for Letterman.

Ratings for “Nightline,” meanwhile, remain elevated, averaging 5 million viewers last week, up 22% from the same week last year.

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Brian Lowry