Fox scored a Monday ratings victory among young adults behind action dramas “24” and “Prison Break,” according to preliminary nationals from Nielsen.

“Prison Break” (4.5 rating/12 share in adults 18-49, 10.1 million viewers overall) opened the night up a bit from its spring premiere of a week earlier, and that boosted “24” (6.0/14 in 18-49, 14.5 million viewers overall), which had its best showing since its premiere on Jan. 16.

Fox may have benefited from CBS airing mostly repeats on the night, with the Eye led by “CSI: Miami” at 10 (5.2/14 in 18-49, 16.2 million viewers overall). Only CBS original Monday was new 9:30 laffer “Old Christine” (3.8/9 in 18-49, 12.1 million viewers overall), which retained a nothing-special 84% of its demo lead-in from a repeat “Two and a Half Men” (4.5/10 in 18-49, 14.1 million viewers overall); “Christine” had held more than 90% of “Men” in its first two tries in the timeslot.

NBC got off to another good start with “Deal or No Deal” (5.0/13 in 18-49, 16.0 million viewers overall), and “The Apprentice 5” held steady at 9 (4.1/9 in 18-49, 10.2 million viewers overall). At 10, a special repeat of last Wednesday’s series premiere of “Heist” performed weakly (2.3/6 in 18-49, 6.0 million viewers overall).

ABC, which tied ABC for third in 18-49, received solid scores from “Wife Swap” (3.8/10 in 18-49, 9.1 million viewers overall) and “Supernanny” (4.2/10 in 18-49, 9.9 million viewers overall), and 10 o’clock newbie “Miracle Workers” was up week to week (3.4/9 in 18-49, 8.8 million viewers overall).

Preliminary 18-49 averages for the night: Fox, 5.2/13; CBS, 4.0/10; ABC, 3.8/10; NBC, 3.8/10; UPN, 1.4/3; WB, 1.3/3.

In total viewers: CBS, 12.4 million; Fox, 12.3 million; NBC, 10.7 million; ABC, 9.3 million; WB, 3.5 million; UPN, 3.2 million.