HOLLYWOOD — Fox soap “The OC” lathered up stronger ratings in its second outing Tuesday, a good sign for a show headed for a tough Thursday timeslot this fall.

According to Nielsen, “OC” led its 9 o’clock hour (3.5/10 in adults 18-49, 7.86 million viewers overall), rising 21% in 18-49 from its modest debut a week earlier. Remarkably, this is the largest week-to-week build for any series on any net since a 23% climb for the original “Survivor” on CBS in June 2000 (7.5/25 from 6.1/20).

“OC” also built nicely in its second half-hour Tuesday in all key categories, including 15% in 18-49 (3.3/10 vs. 3.8/11) and 18% in 12-34 (3.8/13 vs. 4.5/15).

Lesser competition

Not having to face NBC’s “Last Comic Standing” certainly helped the Fox drama, but so did the two additional airings of the first show on Fox during the past week. Net reported that an unduplicated audience of 22 million had watched at least six minutes of the show’s first episode.

Fox will continue to triple-pump “OC” the next two weeks, with showings Friday at 9 and Monday at 8. Skein is tapped for Thursdays at 9 this fall following the net’s coverage of the Major League Baseball playoffs.

Elsewhere on the night, CBS reality skein “Big Brother 4,” without competish from an NBC unscripted skein for the first time, hit a Tuesday high and dominated at 8 (4.0/14 in A18-49, 9.68m) — the net’s best 18-49 score in the hour in 18 months.

Over the past week, all three nights of “Big Bro” have set summer highs.

‘Cupid’ edges up

At 9, “Cupid” (2.8/8 in A18-49, 5.98m) was up week-to-week but still is performing below the levels attained when it aired Wednesdays at 10. It ran second in 18-49.

“Miss Teen USA” (2.5/8 in 18-49, 7.09m), airing on NBC for the first time, was on par with its scores from last season on CBS (2.6/7, 6.29m). Pageant, co-hosted by Mario Lopez and Brooke Burns, ran in an earlier timeslot this year, from 8 to 10.

At 10, Bravo’s “Queer Eye for the Straight Guy” (1.3/4 in A18-49, 2.27m) was down 19% week-to-week in the demo, while FX’s “Nip/Tuck” remained strong, off 6% in 18-49 to 1.7/5 in and 3.35 million viewers overall.

The season finale of MTV’s “The Osbournes” placed a lackluster fifth in the 10:30 half-hour among adults 18-49 (1.5/5) — behind NBC, ABC, CBS and FX — and averaged 2.79 million viewers overall.

At 9, Bravo’s “Boy Meets Boy” (0.7/2 in A18-49, 1.06m) was down 10% vs. last week in 18-49.