The famous zip is still hip.

Young auds returned to “90210” on Tuesday, as CW’s update of the iconic Fox sudser “Beverly Hills 90210” set network records for a premiere.

No net had more riding on a single show this fall than the CW on a new spin on the high school-set drama — and so far, so good. Show got strong sampling with its early premiere, but must brace for some brutal competish in coming weeks.

For CW, the strong launch of “90210” gave the net two potent preem nights this week, following “Gossip Girl” and “One Tree Hill” on Monday (Daily Variety, Sept. 3).

“Our strategy was to be able to get out ahead of the other networks,” CW Entertainment prexy Dawn Ostroff said. “It gives us a chance to get the shows exposed to a wider audience. It’s been challenging for us to compete with everyone launching at the same time.”

She said the net aired two back-to-back episodes in order to create a bigger event.

“We wanted people to feel like it was worth coming to. It’s a very tricky time (ratings-wise). To have these kinds of numbers during a time like this, with our young audience, is huge.”

In its debut, according to preliminary Nielsen estimates, “90210” averaged a 2.6 rating/7 share in adults 18-49 and 4.9 million viewers overall, winning in the net’s target demo of adults 18-34 (3.0/9) as well as women 18-34 (4.3/12). And in a good sign, “90210” built its audience a bit from its first hour to its second.

The 2.6 rating in 18-49 easily tops the best for any scripted episode of a CW series to date (2.2 for a “Smallville” seg in 2006).

CBS Paramount Network TV topper David Stapf credited the CW for its marketing campaign on “90210,” as well exec producers Jeff Judah and Gabe Sachs — who, he said, were able to adapt the original “90210’s” tone and update it for 2008 auds.

“The original show was incredibly successful; it knew what it was,” Stapf said. “They took a cue from that but made (the new version) its own, relevant, show. The writers and everyone involved did a good job in achieving both.”

While “90210” didn’t fare especially well among teens 12-17 (1.7/6), it must build a new franchise with this crowd — too young to remember the original, which aired on Fox from 1990 to 2000. In a bid to recruit more new viewers prior to next week, CW will replay the two-hour preem tonight.

Even if its ratings drop off a bit in coming weeks, “90210” figures to give the struggling net a strong presence in what could be TV’s most competitive hour this fall. In coming weeks, the drama will face tough competish for its target young female aud from Fox’s “House” and NBC’s “The Biggest Loser,” among others.

CW is pairing “90210” with another new drama, “Privileged,” which bows at 9 next week.

Elsewhere Tuesday, NBC’s “America’s Got Talent” led in broader categories from 8 to 10 p.m. (prelim 2.8/8 in 18-49, 10.6 million), while CBS’ “Big Brother” was up a bit week to week at 9 p.m. (prelim 2.4/6 in 18-49, 6.4 million).

Due to holiday-related delays, Nielsen did not report national estimates for Tuesday’s coverage of the Republican National Convention on Wednesday.

In affiliate-based prelims, though, ABC, CBS and NBC combined to attract 10.8 million viewers during the 10 o’clock hour, down from the 13.6 million that the Democrats garnered in prelims a week ago.

(Michael Schneider contributed to this report.)

TV Review: “90210”