There was no clear cut winner in Thursday’s primetime ratings race, with NBC having the edge among young adults but ABC and CBS both within shouting distance, according to preliminary Nielsen nationals.

The Peacock was solid but unspectacular, paced by a time-slot winning perf by “ER” (5.7/15 in 18-49, 13.6 million viewers overall), which remained on the low side of its ratings range despite lack of drama competish from CBS’ “Without a Trace.” At 9, “My Name is Earl” (5.2/13 in 18-49, 11.3 million viewers overall) bounced back from its firstrun season low a week earlier, as the net improved its position at 8:30 with a repeat “Earl” (3.8/10 in 18-49, 8.7 million viewers overall) in place of “Four Kings.” A repeat “The Office” netted a 4.1/10 in 18-49 and 8.6 million viewers overall at 9:30.

ABC did OK with the first of its special Hurricane Katrina-related “Extreme Makeover: Home Edition” specials on the night (3.6/10 in 18-49, 10.7 million viewers overall), and then picked up at 9 with week two of “American Inventor” (5.1/13 in 18-49, 13 million viewers overall), which was down a bit from its premiere. Net closed strong with “Primetime” (4.5/12 in 18-49, 10.9 million viewers overall), which logged its best 18-49 average since November 2003.

CBS was the night’s most watched net overall, averaging roughly 12.5 million viewers and a 4.3 rating/11 share in adults 18-49 with its coverage of third-round NCAA men’s basketball tourney action. These numbers are subject to revision due to games airing in different timezones in various parts of the country.

Fox was the laggard among the Big Four with its lineup of “That ’70s Show” (2.6/7 in 18-49, 5.4 million viewers overall), “The Loop” (2.1/6 in 18-49, 4.3 million viewers overall) and “The OC” (2.5/6 in 18-49, 5.3 million viewers overall). All three shows were up a smidge week to week.

Preliminary 18-49 averages for the night: NBC, 4.7/12; ABC, 4.4/12; CBS, 4.3/11; Fox, 2.4/6; WB, 1.2/3; UPN, 1.2/3.

In total viewers: CBS, 12.5 million; ABC, 11.5 million; NBC, 10.8 million; Fox, 5.1 million; WB, 2.9 million; UPN, 2.8 million.