Leno’s Winning Streak Over: Dave Back on Top

Letterman defeats Jay in key demos, ending whatever post-Olympics glow “The Tonight Show” had. The war continues…

Last Updated: March 9, 2010 @ 7:47 PM

Jay Leno’s one-week winning streak is over.

Monday’s "Late Show with David Letterman" beat "The Tonight Show with Jay Leno" in adults 18-49 and adults 25-54, the demographic groups that matter most to advertisers. That’s according to preliminary fast national Nielsen data just released.

Leno still eked out a win in total viewers, drawing 4.36 million vs. Letterman’s 4.19 million.

But in adults 18-49, it was Dave 1.3/6 and Jay 1.1/5. Among adults 25-54, Dave notched a 1.6 vs. a 1.4 for Jay.

Leno’s "Tonight" reboot had won its first five nights in viewers and demo last week.

But Monday, NBC’s primetime average took a big hit, with "Trauma" tanking and "Law & Order" slipping below Leno Monday averages. The lower lead-in resulted in the Leno loss.

It’s just one night, of course. And NBC insiders have been insisting that they think it will take months for Leno to regain the regular lead he had over Dave before the whole LateNight Mess began.

But the fact that Leno lost to Letterman so soon indicates that any post-Olympics halo is gone.