NBC’s rookie psychic drama “Medium” is showing no signs of slowing down, topping a repeat of CBS’ “CSI: Miami” to stand as Monday’s top-rated program, according to preliminary nationals from Nielsen. Fox’s “24” also continues to look good on its new night.

In the 10 o’clock hour, “Medium” (6.1 rating/15 share in adults 18-49, 15.7 million viewers overall) was on par with its prior three-week average, winning opposite “CSI: Miami” (5.3/13 in adults 18-49, 14.8 million viewers overall) and week two of ABC’s “Supernanny” (3.9/10 in adults 18-49, 9.3 million viewers overall). Latter was up a bit in demos vs. its premiere.

Fox’s “24” (5.1/12 in adults 18-49, 12.2 million viewers overall) led the 9 o’clock hour in adults 18-49 over NBC’s “Las Vegas” (4.8/11 in adults 18-49, 12.2 million viewers overall), although the latter was the top choice among viewers under 35. CBS topped the hour in total viewers but was third in 18-49 with “Everybody Loves Raymond” (4.6/11 in adults 18-49, 14.9 million viewers overall) and “Two and a Half Men” (4.6/10 in adults 18-49, 13.6 million viewers overall).

From 8 to 9, NBC ruled with “Fear Factor” (4.8/12 in adults 18-49, 11.3 million viewers overall), with Fox’s “Trading Spouses” placing second in demos (3.5/9 in adults 18-49, 7.9 million viewers overall). Over at the WB, the birth of Lucy Camden’s baby propelled “7th Heaven” to season-high ratings (2.9/8 in adults 18-49, 8.1 million viewers overall).

Of note in latenight, “The Tonight Show with Jay Leno” averaged a big 11.2 household rating/26 share in local metered-market overnights with a special tribute to the late Johnny Carson and guests including Ed McMahon. This is the fourth-highest score since Leno took over the program, trailing only the night of the “Cheers” finale in 1993, Leno’s premiere as host in 1992 and the night of the “Seinfeld” finale in 1998.

Preliminary 18-49 averages for the night: NBC, 5.2/13; Fox, 4.3/10; CBS, 4.2/10; ABC, 3.6/9; WB, 2.3/6; UPN, 1.3/3.

In total viewers: NBC, 13.1 million; CBS, 12.6 million; Fox, 10.0 million; ABC, 8.8 million; WB, 6.3 million; UPN, 3.2 million.