By Lynette Rice
Updated June 25, 2009 at 08:42 PM EDT

The late-night wars are definitely heating up: For the week ending June 19, CBS’ The Late Show With David Letterman beat The Tonight Show in viewers for the first time since December 2005. In the third week since Conan O’Brien took over The Tonight Show, Letterman averaged 3.46 million viewers — a 13 percent jump compared to the same week last year. O’Brien, in comparison, averaged 3.32 million viewers, up 4 percent from the previous year.

O’Brien still won the week among adults 18-49, but Letterman trailed by just one-half a rating point.