Fueled by its “American Idol” lead-in, the Wednesday premiere of “The Simple Life 3: Interns” scored the series’ highest-ever viewership and second-best figures in adults 18-49.

The return of the reality sitcom, which this time follows Hilton and pal Nicole Richie as they intern for various companies, averaged a 6.2 rating/14 share in the young adult demo and 13.4 million viewers. That bests the premieres of “The Simple Life” and “Simple Life 2.”

As a result, “Simple Life 3” dominated the 9 p.m. hour in total viewers and adults 18-49, 18-34 and 25-54.

Given another big performance from “American Idol” (11.2 rating/28 share in adults 18-49, 26.5 million viewers), Fox easily won the night in all measurements (including 8.7/21 in adults 18-49).

CBS squeaked out a second-place win among adults 18-49 thanks to an original episode of “CSI: NY” at 10 p.m. Show had lighter competition than usual, going up against a repeat of ABC’s “Wife Swap” and NBC’s Katie Couric special “The 411: Teens & Sex” (which preempted “Law & Order”).

With two-thirds of its night in repeats (both “Swap” and “Lost”), ABC wound up third (3.9/10) in the demo.

“Sports Illustrated Swimsuit Model Search” did NBC no favors, meanwhile, posting a 1.6/4 in the demo. The reality competish is averaging just a 2.1/5 with adults 18-49 — lower than the two canceled shows that preceded it in the slot (“Hawaii” and “LAX”). Show is NBC’s lowest-rated regular-season series since “Hunter” briefly returned in spring 2003.

For the night, Peacock posted a 2.8/7 with adults 18-49. Over at the WB, the return of “Jack & Bobby” to its Wednesday night slot averaged a 1.2 rating/3 share in viewers 12-34, on par with the show’s prior performance. Frog averaged a 1.4/3 for the night with adults 18-49, while UPN clocked in with a 0.9/2.