NBC’s rookie drama “Medium” and the second part of Fox’s two-night season premiere of “24” ruled the ratings roost on Monday, according to preliminary nationals from Nielsen, while ABC also did well with the series premiere of a spinoff of Sunday smash “Extreme Makeover: Home Edition.”

In the 10 o’clock hour, psychic drama “Medium” (6.3/15 in adults 18-49, 16.3 million viewers overall) was on par with its impressive week-earlier bow – winning its hour over a repeat of “CSI: Miami” on CBS (4.7/11 in adults 18-49, 13.8 million viewers overall) and the second half of the premiere of ABC’s “The Bachelorette.” NBC also did pretty well at 9 with “Las Vegas” (4.7/11 in adults 18-49, 13.8 million viewers overall) and was competitive, but is no longer the undisputed leader, at 8 with “Fear Factor” (4.3/11 in adults 18-49, 10.7 million viewers overall).

Fox aired another two hours of “24” on the night, winning across the board at 8 (4.6/12 in adults 18-49, 11.9 million viewers overall) and leading in 18-49 in its regular slot at 9 (5.3/12 in adults 18-49, 13.3 million viewers overall). The victory at 9 marked the first time this season that a regular, firstrun scripted Fox series won its time period in 18-49.

ABC, rejigging its sked in the absence of “Monday Night Football,” did very well at 8 with “Extreme Makeover Home Edition: How’d They Do That” (4.3/11 in adults 18-49, 11.6 million viewers overall), which was in a tight three-way race with Fox and NBC for the hour’s 18-49 lead with the net’s best result in the time period with an entertainment series in nearly seven years. And from 9 to 11, the season premiere of “The Bachelorette” opened with some spunk (4.3/10 in adults 18-49, 9.2 million viewers overall), growing nicely each half-hour.

CBS went with all repeats, led by “Everybody Loves Raymond” (5/12 in adults 18-49, 15.8 million viewers overall).

At the WB, the “Critics Choice Awards” settled for a 1/2 in adults 18-49 and 2.7 million viewers overall.

Preliminary 18-49 averages for the night: NBC, 5.1/12; Fox, 5.0/12; ABC, 4.3/10; CBS, 4.2/10; UPN, 1.2/3; WB, 1/2.

In total viewers: NBC, 13.2 million; CBS, 12.8 million; Fox, 12.6 million; ABC, 10 million; UPN, 2.9 million; WB, 2.7 million;