Don’t count out the Peacock just yet.

Although not the dominant force it was a year ago during a month celebrating its 75th anniversary, NBC remains the young-adults ratings leader at the halfway point of the May sweep — barely holding off a charging Fox.

Peacock, the season leader in the key sales demo of adults 18-49, has seen steep declines by anchor shows “Frasier” and “West Wing” this month and is hurting on the weekend, where it no longer gets a boost from the NBA playoffs. Net is off 19% vs. a year ago, enabling Fox, which is up by 19%, to stay close and likely win the month behind expected boffo ratings for the final two nights of “American Idol.”

NBC was at a 4.4 rating/12 share in the 18-49 demo through two weeks, slightly ahead of Fox’s 4.3/12, according to Nielsen.

“Idol” hit three-month ratings highs on Wednesday and “Bernie Mac” hit another series record as the Murdoch net wrapped the midway point of the sweep an easy winner. Fox and the WB are the only nets showing year-to-year gains, with the Frog’s “Dawson’s Creek” putting up big numbers on Wednesday one week from its series finale.

CBS, despite modest year-to-year declines, is delivering the largest overall audience and is on pace to win its second May sweeps crown in three years by this measure.

ABC, down slightly in key demos, could finish with year-to-year growth thanks in part to “The Bachelor,” which Wednesday hit a new high for its current edition and still has its two-hour finale to come. Picture is bleakest for UPN, which is down by double-digit percentages across the board.

On Wednesday, Fox cruised to victory behind the 30-minute “American Idol” results show (10.4/27 in adults 18-49, 22.69 million viewers overall), which rang up its best numbers on the night since late January.

Laffers “That ’70s Show” at 8 (5.8/18 in adults 18-49) and “Bernie Mac” at 9 (series record 6.5/16) also led their slots in 18-49, with a second original “Bernie” at 9:30 (5.3/13) placing second.

Young women went from watching “Idol” at 8:30 to ABC’s “The Bachelor” at 9, with the dating show hitting a new high for its current edition (6.6/16 in A18-49, 13.51m) and winning its hour for a second straight week. Net’s opening-hour laffers also were solid, with “My Wife and Kids” (3.5/11 in A18-49) and “George Lopez” (3.6/9) both second in their slots, with the latter featuring a guest appearance by Cristina and hitting a two-month high.

ABC was second to Fox on the night in both 18-49 (5.0/13 vs. 7.1/19) and 18-34 (5.0/15 vs. 7.5/22).

The WB’s “Dawson’s Creek,” despite facing “Idol,” racked up its best numbers of the year (2.7/8 in A18-49, 4.88m), shooting up to a second-place 4.1/13 in adults 18-34 and 5.7/15 in women 18-34 — its best score since November 2000. Net’s “Angel,” whose status for next season remains unclear, was up a tick week-to-week with its season finale (2.6/7 in A18-34).

For the month, the WB is up 5% year-to-year in adults 18-34 (fifth-place 2.1/7) and is fourth for the sweep among persons 12-34 (2.2/8).

NBC was third on the night in 18-49 and second in 25-54, led by “Law & Order” (6.0/16 in A18-49, 17.46m), which led at 10. “West Wing,” one week from its season finale, was on par with its recent scores (4.4/11 in A18-49, 13.37m).

CBS, third for the sweep in adults 18-49 (down 8%) and second in 25-54 (down 6%), had a slow Wednesday. “Star Search” (2.4/7 in A18-49, 9.51m) was up week-to-week, though.