Boosted by the Gov. Sarah Palin controversy, David Letterman’s “Late Show” on CBS last week drew more viewers than NBC’s “The Tonight Show” for the first time in more than 3 1/2 years.

Though the Conan O’Brien-hosted “Tonight Show” continues to dominate the 11:35 p.m. hour among young adults, the race for overall viewership is tight most weeks. Of course, the complete latenight story won’t unfold until the fall, as it remains to be seen what effect Jay Leno’s new weeknight show at 10 o’clock will have.

Looking at the June 15-19 sesh, Letterman opened with a big Monday victory in total viewers — thanks to his apology to Palin for comments he made about her on his program — and then held on to win (3.46 million to 3.32 million). It was “Late Show’s” first victory over a full week of “Tonight Show” originals since December 2005.

The story was different in demos, where “Tonight” (in O’Brien’s third week as host) held a sizable 67% advantage over “Late Show” among adults 18-49 (1.8 million to 1.1 million).

NBC points out that “Tonight Show” is delivering a much more balanced aud than “Late Show,” with O’Brien averaging a rating of 1.3 to 1.5 in adults 18-34, 18-49, 25-54 and 55-plus. Letterman, on the other hand, drew ratings of 0.5, 0.8 and 1.1, respectively, in the younger demos and a 2.7 rating among those 55-plus.

In other ratings of note, NBC’s premiere of international co-production drama “The Philanthropist,” starring James Purefoy, averaged a solid-enough 1.9/6 in 18-49 and 7.12 million viewers overall. It won its 10 p.m. hour in 18-49, taking advantage of its lead-in from “America’s Got Talent” (3.1/9, 10.40m).

ABC News’ hourlong spec “Questions for the President: Prescription for America” drew 4.65 million viewers Wednesday at 10 p.m. — good by the standards of the net’s weak showing in the timeslot this summer but still well behind NBC’s “The Philanthropist” and CBS’ repeat of “CSI: NY” (7.43m).

It skewed pretty old, too, running fourth for its hour in adults 18-49 (1.1/3) and third in adults 25-54 (1.4/4).

A continuation of the Obama conversation at 11:35 p.m., however, did provide a boost for the Alphabet’s “Nightline.” According to preliminary Nielsen nationals, “Nightline” averaged 4.25 million to 3.66 million for NBC’s “Tonight” and 3.23 million for CBS’ “Late Show.”