HOLLYWOOD — Sweeps demo leader NBC scored another pair of victories on Thursday and Friday, but continues to be hounded on the former night by CBS.

According to Nielsen, the Peacock net captured Thursday by 7 shares in adults 18-49 over the second-place Eye (8.9/24 vs. 6.3/17) and by less than 1 million viewers overall (17.4m vs. 16.8m). Though remaining the strongest primetime lineup on any net, NBC’s Thursday saw declines vs. the same night a year ago of 30% and 28% respectively, while CBS was up by 77% and 200%.

The night’s most intriguing battle came at 10, where a heavily hyped “ER” dominated its hour (23.17 million, 11.5/30 in adults 18-49) but with its second weakest demo score ever for a firstrun Thursday episode (behind only the previous week). A repeat seg of CBS rookie hit “CSI: Crime Scene Investigation” posted strong numbers in the hour (15.16m, 6.0/16) and certainly cut into the Peacock medical drama, which was down year-to-year by 29% in 18-49.

“CSI” also scored boffo marks with an original episode in its regular hour, taking the hour in total viewers (18.90m) and adults 25-54 (8.8/20) and finishing 2 shares behind NBC’s hourlong score for “Will & Grace” and “Just Shoot Me.”

NBC down by 27%

NBC’s 8-10 p.m. block was down by 27% in adults 18-49 vs. a year ago (7.6/21 vs. 10.5/30).

Net’s stunting of quizzer “Weakest Link” largely fizzled, as the special 30-minute episode featuring players from the original “Survivor” retained a mediocre 80% of its “Friends” 18-49 lead-in (6.9/19 vs. 8.6/27). It edged out the second half-hour of CBS’ “Survivor: Back From the Outback” retrospective in 18-49 (6.9/19 vs. 6.6/19) but the spec won easily in viewers (17.17m vs. 13.65m).

“Back From the Outback,” which followed the “Survivor II” contestants after they returned from Australia, helped CBS milk another week of strong numbers from the reality adventures series. Its scores (16.26m, 6.1/18 in A18-49) were a little more than half of what the series’ regular segs had averaged but still performed considerably better than the Eye’s best non- “Survivor” score in the 8 p.m. hour this season (a Faith Hill spec averaged 13.8 million viewers and a 4.6/13 in 18-49 on Thanksgiving night).

Fox’s “Surprise Wedding 2” scored 23% below the first spec’s scores in 18-49 (3.0/8 vs. 3.9/10, but built throughout its two hours and gave Fox its best women 18-34 rating on a Thursday (4.2/11) since that first spec on Nov. 2.

‘Girls’ gain

Season finale of “Gilmore Girls” did well (4.31m, 1.7/5 in A18-49), but UPN’s “WWF Smackdown” (5.93m, 2.3/6) didn’t see a post-“Survivor” boost, falling 18% shy of last year’s demo score.

NBC captured Friday with a prelim 3.7/13 score in adults 18-49 and 12.3 million viewers, led once again by “Law & Order: SVU.” Its second season finale easily won the 10 p.m. hour (prelim 14.8m, 4.7/15 in A18-49).

The fifth and final night of celebrity “Who Wants to Be a Millionaire” won the night’s opening hour (prelim 12.3m, 3.3/13 in A18-49), giving ABC a demo win in Friday’s opening two half-hours for the first time since a “Funniest Home Videos” spec on Dec. 1. Net didn’t fare as well with Paul McCartney spec “Wingspan” (7.9m, 3.3/11), which placed third for its two-hour block in viewers and second in the demo.

CBS was third in total viewers (prelim 7.8m) and fourth in 18-49 (prelim 2.3/8) as the “Miss Universe Pageant” (prelim 8.4m, 2.7/9 in A18-49) was about 10% lower in the demo year-to-year. Fox was third in 18-49 (2.7/10) and second in 18-34 (2.4/10).

ABC won its second consecutive Saturday in adults 18-49 and other key demos with the network preem of “Speed 2” (prelim 6.8m, 2.8/10 in A18-49). Fox’s reality staples were relegated to runner-up status in adults 18-49 (prelim 2.7/10) for a second straight week even though it won each of its half-hours; ABC moved on top for the night by winning the 10 p.m. hour that Fox doesn’t program.

NBC didn’t do much with the network preem of “Sphere” (prelim 5.4m, 2.3/8 in A18-49), while a new “Dr. Quinn, Medicine Movie” helped CBS win the night in total viewers (prelim 9.4m) but kept it fourth in demos.