NBC wrapped up the third week of May sweeps with its most dominant Wednesday victory in more than nine years, led by the highest-rated one-hour “West Wing” ever and the most-watched episode in the 11-year history of “Law & Order.”

According to Nielsen, the Peacock web topped second place Fox by 46% in adults 18-49 on the night (7.0/19 vs. 4.8/13) for its widest margin of victory with regular programming since January 1992. And in total viewers, NBC’s 8.5 million person-advantage over second-place ABC is its largest on a Wednesday since at least the advent of Nielsen’s People Meters in 1987.

Compared with the same May sweep night a year ago, NBC was up 49% in the demo and 36% in viewers.

Lead widens

Big night has helped the Peacock web expand its lead for the month in 18-49, taking a 14% advantage over Fox into the final seven nights. Net is well on its way to a seventh straight May sweep crown by that measure.

After a solid second-place finish at 8 p.m. for “Ed” (4.0/12 in adults 18-49), “West Wing” followed with its second best ratings ever (20.72m, 7.9/19 in A18-49) — behind only its two-hour season preem last October. Compared with its first season finale last May, “Wing” was up a boffo 84% in 18-49 and 56% in total viewers.

And at 10, 11-year vet “Law & Order” hit an all-time high in total viewers (21.55m) and adults 18-49 (9.2/24), winning its hour in the latter by 13 shares.

Wednesday also saw a rebound for Fox’s “Boot Camp,” season highs for the WB’s “Dawson’s Creek” and more disappointing numbers for CBS mini “Blonde.”

“Boot Camp” enlisted its best ratings in three weeks (10.39m, 5.1/12 in A18-49), returning to a solid second in the demo and first place in adults 18-34 (6.2/16). That helped give Fox the night by a tick over NBC in 18-34 (5.4/16 vs. 5.4/13).

Net’s 8 o’clock comedies gave “Boot” a boost by winning their half-hours in adults 18-49 and younger demos, with both a repeat of “That ’70s Show” (4.6/15) and an original “Grounded for Life” (4.4/13) logging their best scores in 11 weeks.

The graduation episode of “Dawson’s Creek” hit season highs in viewers (5.45m), persons 12-34 (4.1/14) and women 18-49 (3.9/11), among other demos. It won its hour by 3 shares in women 18-34 (5.7/17).

For the sweep, the Frog net is up 23% in women 18-34 vs. a year ago.

ABC had a rather uneventful night, although a special episode of “Who Wants to Be a Millionaire” (13.44m, 4.3/11 in A18-49) logged solid num-bers opposite “Law & Order.”

CBS was fourth in viewers and adults 18-49 (2.7/7) as Marilyn Monroe mini “Blonde” (8.79m, 2.8/7 in A18-49) fell by about 23% from its medio-cre Sunday opener.

The penultimate episode of “Star Trek: Voyager” (5.55m, 2.9/7 in A18-49) grabbed the series’ top marks in 11 weeks.

Through 21 nights of the four-week May sweep, standings in adults 18-49 are: NBC, 4.8 rating/14 share (down 8% in rating vs. a year ago); Fox, 4.2/12 (up 2%); CBS, 4.1/12 (up 17%); ABC, 3.9/11 (down 29%); the WB, 1.7/5 (up 21%); and UPN, 1.6/5 (down 6%).

In total viewers: CBS, 12.94 mil-lion (up 9% vs. a year ago); NBC, 11.70m (down 4%); ABC, 10.80m (down 30%); Fox, 8.71m (up 4%); the WB, 3.70m (up 8%); and UPN, 3.66m (down 9%).

NBC leads CBS by 14% in adults 25-54 (5.6/15 vs. 4.9/13) while Fox has a 7% advantage over NBC in adults 18-34 (4.4/14 vs. 4.1/13).