Its new unscripted series “Wickedly Perfect” didn’t do much, but CBS won the first Thursday of the new year thanks to a dominant perf by “CSI” and record ratings for “Without a Trace,” according to preliminary nationals from Nielsen.

“CSI” rolled at 9 (9.6 rating/23 share in adults 18-49, 28.7 million viewers overall) but was on the low end of its firstrun ratings range, getting little help from its lead-in from “Wickedly Perfect” (3.0/8, 9.8 million viewers overall). Latter domestic-diva skein delivered the lowest firstrun in-season demo scores in the Thursday-at-8 hour for the Eye since October 2000, although it did pick up in the second half-hour and placed second in total viewers.

Big story of the night for CBS, though, was the record highs at 10 for “Without a Trace” (7.7/20 in adults 18-49, 23.7 million viewers overall), which retained a strong 80% of its “CSI” lead-in. “Trace” beat the combined scores of NBC’s repeat of new Monday drama “Medium” (4.2/11 in adults 18-49, 9.3 million viewers overall) and ABC’s “Primetime” (2.7/7 in adults 18-49, 8.6 million viewers overall).

NBC was paced by “Joey” (5.1/14 in adults 18-49, 12.5 million viewers overall), which took advantage of “Survivor’s” absence to log its best score since Nov. 11. A special firstrun seg of Tuesday comedy “Committed” followed at 8:30, looking solid and winning its half-hour (5.0/13 in adults 18-49, 11.6 million viewers overall).

Fox’s “The OC” (3.3/9 in adults 18-49, 7.6 million viewers overall) also seemed to benefit from CBS’ softness in the hour, placing second in 18-49 and first in persons 12-34.

And at ABC, “Life as We Know It” (1.4/4 in adults 18-49, 4.3 million viewers overall) and “Extreme Makeover” (1.9/5 in adults 18-49, 6.0 million viewers overall) performed similar to prior levels despite switching timeslots. But the higher rating in the 9 o’clock hour did seem to boost “Primetime,” which hit a season high.

Preliminary 18-49 averages for the night: CBS, 6.8/18; NBC, 4.7/12; Fox, 2.5/6; ABC, 2.0/5; UPN, 2.0/5; WB, 1.2/3.

In total viewers: CBS, 20.7 million; NBC, 10.4 million; ABC, 6.3 million; Fox, 5.9 million; UPN, 5.3 million; WB, 2.8 million.