NBC’s primetime struggles appear to be spilling over into latenight, where “The Tonight Show With Jay Leno” fell behind CBS’ “Late Show With David Letterman” in demos for the first full week of the November sweep.

Nielsen estimates that Letterman’s show topped Leno in adults 18-49 (1.20 million to 1.04 million) during the Oct. 31-Nov. 4 frame, with the former down 1% vs. the comparable week of last year and the latter down 17%. “Tonight” still held the edge in total viewers (3.58 million vs. 3.54 million) but that gap closed.

The Eye had the clear edge in the 10:30 p.m. half-hour leading into the late local news, where its average weeknight 18-49 score (2.6 rating/7 share) repped a big 73% advantage over NBC (1.5/4). CBS was even more dominant at 10:30 p.m. in adults 25-54 (3.5/9 to 1.9/5) and total viewers (11.74 million to 5.04 million).

CBS also held the edge over NBC at 12:35 a.m., where “Late, Late Show With Craig Ferguson” moved ahead of “Late Night With Jimmy Fallon” in adults 18-49 (724,000 vs 718,000), with the Eye show up 11% from last year and the Peacock skein down 13%. In total viewers, each show drew about 1.75 million.

ABC’s 25-minute “Nightline” was latenight’s No. 1 program in 18-49 (1.25 million), 25-54 (1.59 million) and total viewers (3.91 million) — on par with last year. Following the news program, “Jimmy Kimmel Live” averaged 714,000 adults 18-49 and 1.87 million viewers overall, up a bit in the demo vs. last year.

NBC had better latenight news with “Saturday Night Live,” whose Nov. 5 telecast hosted by Charlie Day averaged 3.22 million adults 18-49 (up 31% vs. the same week a year ago) and 6.55 million viewers overall (up 16%). This is the best demo score for the show since last May’s season finale with Justin Timberlake and Lady Gaga.