While “Lights” did manage to finish second in its very weak timeslot for its season two premiere, its numbers weren’t all that promising.

“Lights” averaged a 2.1 in adults 18-49 at 9 p.m. Friday, according to final Nielsen numbers, just behind CBS’s critically derided new vampire drama “Moonlight” in that demo while drawing 6.5 million total viewers. That made it NBC’s least-watched program of the night.

The timeslot competition included two reruns, ABC’s “Private Practice” and Fox’s “K-Ville,” as well as CW’s “Smackdown,” which does well in the younger 18-34 demographic.

But the lighter competition didn’t boost “Lights’” average. The show was slightly off from last year’s season average of 2.2 and was down 22 percent from last year’s premiere, which averaged a 2.7.

Perhaps some “Lights” fans didn’t know the show had moved, or maybe it was actually hurt by Friday night’s generally low viewership levels. Whatever the reason, NBC will probably want to see stronger results to keep the show on the air.

“Lights” could still see a kick-up in viewership when digital video recorder ratings are released in a few weeks. The percentage of DVR households in Nielsen’s sample has more than doubled since this time last year, and media people expect seven-day-playback ratings to influence networks’ decisions on what to keep on the air.

Meanwhile, “Moonlight” saw a sharp decline from its opener, dipping 19 percent from a 2.7 last week to a 2.2. Media people were surprised the show, whose pilot was reshot shortly after May’s upfront, had debuted so strongly.

CBS still managed to take the night easily, even with a weaker “Moonlight.” The network averaged a 2.5 18-49 rating and 8 share, with NBC second at 2.1/7, ABC third with 1.8/6 and Fox and the CW tied for fourth at 1.4/5. Univision’s ratings weren’t available at press time.

CBS led every hour, with “Ghost Whisperer” first at 8 p.m. at 2.5, followed by NBC’s “Deal or No Deal” at 2.1, Fox’s “Are You Smarter Than a 5th Grader” at 1.5, ABC’s “Pushing Daisies” rerun at 1.4, and the first hour of “Smackdown” on the CW at 1.3.

At 9 p.m., CBS led with “Moonlight” at 2.2, followed by "Lights'" 2.1. ABC’s “Private” rerun was second at 1.7, followed by the CW’s conclusion of “Smackdown” at 1.5 and Fox’s “K-Ville” rerun at 1.2.

At 10 p.m., CBS’s “Numb3rs” placed first with a 2.8, with ABC’s “20/20” second at 2.3 and NBC’s “Las Vegas” at 2.2, down 8 percent from last week’s 2.4 for its two-hour premiere.

Among households, CBS led easily at 5.8/11, followed by NBC at 4.9/9, ABC at 3.8/7, Fox at 2.7/5 and the CW at 2.5/5.