"The Tonight Show with Conan O’Brien" continued to dominate the late night ratings, notching its fourth straight demographic victory over "Late Show David Letterman" during the week ending June 26.

O’Brien also regained his lead over CBS’s "Late Show" among total viewers, according to Nielsen. Letterman’s broadcast, boosted by the host’s Sarah Palin squabble, had squeezed by O’Brien’s show a week earlier.

"Tonight" averaged a 1.4 in the adults 18-49 demo for the week of June 25, compared to a 0.8 for "Late Show."

In overall viewership, "Tonight" averaged 3.69 million viewers, while "Late Show" drew 3.46 million.

ABC’s "Nightline" actually had the biggest average audience of any latenight show for the week, with 3.89 million overall viewers. However, direct comparisons are unfair since the ABC newsmagazine signs off at 12:05, while the other shows are an hour.

"Nightline" was boosted by its exclusive town hall meeting with President Obama and, of course, two nights of Michael Jackson coverage.

–Josef Adalian