Fox cruised to victory Wednesday behind its full-night “American Idol,” but the music contest joined other top shows on the night — ABC’s “Modern Family” and CBS’ “Criminal Minds” — in curiously falling to season lows.

Compared with the last time the three shows faced off in originals against each other, just two weeks earlier, “Idol” fell off by 16%, “Modern Family” by 10% and “Criminal Minds” by 13%.

PUT levels were low, especially kicking off the night, with Nielsen saying that tune-in during the 8 o’clock hour was down from last week by 5% in adults 18-49 and by larger margins in other categories including teens and adults 18-34.

And at 9 p.m., even with “Modern Family” and “Criminal Minds” back in originals, the number of persons using television was surprisingly down week-to-week by 3.3% in 18-49.

Looking at the preliminary national estimates from Nielsen, “American Idol” averaged a 4.6 rating/13 share in adults 18-49 and 14.2 million viewers overall to rule as Wednesday’s top show despite a decline from the 5.5 demo rating it had produced the last two weeks. “Idol” beat “Modern Family” by a big 21% in 18-49.

Elsewhere, ABC remained solid kicking off the night with “The Middle” (2.3/7 in 18-49, 8.4 million viewers overall), which ran second to “Idol.” The net then dropped off at 8:30 p.m. with “The Neighbors” (1.8/5 in 18-49, 6.3 million viewers overall), which is contributing to lower ratings this season for “Modern Family”; on Wednesday, the Emmy winner hit same-night season lows (3.8/10 in 18-49, 10.1 million viewers overall), though it remained the top scripted series in 18-49 and 25-54 (4.6/11). “Suburgatory” (2.1/5 in 18-49, 5.9 million viewers overall) was also below average at 9:30 p.m., though its retention was better than previous weeks, and “Nashville” was down as well at 10 (1.7/5 in 18-49, 5.2 million viewers overall), placing third in the broadcast drama showdown.

CBS, whose “Survivor” returns next week, opened with a special repeat of “Person of Interest” (1.2/4 in 18-49, 7.3 million viewers overall) and then saw “Criminal Minds” produce its season lows (2.7/7 in 18-49, 11.8 million viewers overall). Holding up better, but down from its last original as well, was 10 p.m. vet “CSI” (2.4/7 in 18-49, 10.9 million viewers overall), whose first of a two-night crossover event with Friday cousin “CSI: NY” easily won the hour in 18-49, 25-54 and total viewers.

For the night, CBS was third in 18-49 (just a tick behind second-place ABC) and second in 25-54 and total viewers.

NBC remained sluggish kicking off the night with half-hours “Whitney” (1.2/4 in 18-49, 3.5 million viewers overall) and “Guys with Kids” (1.2/3 in 18-49, 3.2 million viewers overall), and didn’t look much better at 9 p.m. with “Law & Order: SVU” (1.5/4 in 18-49, 5.2 million viewers overall), which has the tough task of going up against the night’s top three programs in 18-49. Rookie drama “Chicago Fire” (1.8/5 in 18-49, 6.5 million viewers overall) joined “SVU” in showing declines from last week when they faced repeats on ABC and CBS, but again building on its “SVU” lead-in and then growing in its second half-hour.

At CW, Wednesday remains the net’s most-watched night of the week. Rookie “Arrow” (1.0/3 in 18-49, 3.0 million viewers overall) was up in key demos, and 9 p.m. vet “Supernatural” (0.9/2 in 18-49, 2.2 million viewers overall) held steady in demos and grew a bit in total viewers.

Preliminary 18-49 averages for the night: Fox, 4.6/13; ABC, 2.2/6; CBS, 2.1/6; NBC, 1.5/4; Univision, 1.4/4; CW, 1.0/3.

In total viewers: Fox, 14.2 million; CBS, 10.0 million; ABC, 6.9 million; NBC, 5.0 million; Univision, 3.6 million; CW, 2.6 million.