Although this television season is still in its early days, CBS appears to be the most successful network so far. For the second consecutive week, CBS managed to win the ratings competition in both total viewers and the 18-to-49-year-old demographic that advertisers keenly hunt, as four of the five most watched programs belonged to the network.

According to estimates released on Tuesday by Nielsen Media Research, CBS claimed the top position on five nights of the week ended October 12, while the network’s “CSI: Crime Scene Investigation” season premiere on Thursday was the week’s highest rated show, with 23.5 million viewers. In addition, CBS’s key-program “CSI” even outshined ABC’s “Grey’s Anatomy,” drawing more young viewers than the medical drama for the first time since the shows kicked off their nose to nose struggle a couple of years ago.

CBS’s “NCIS” was the third most popular show last week, as 16.3 million viewers tuned in for the Tuesday series, while Wednesday saw great performances by “Criminal Minds” (16.19 million viewers) and “CSI: NY” (15.87 million viewers).

Overall, CBS averaged 10.96 million viewers, followed by ABC with 9.59 million viewers, Fox, which lured 7.96 million viewers, NBC with 7.0 million viewers and the CW with 2.1 million viewers.

In spite of the fact that ABC’s “Dancing with the Stars” continues to be a hit, as 18.59 million viewers tuned in for the show, the network’s fresh time-traveling cop drama “Life on Mars” drew only 11.3 million viewers, as audiences also watched CBS’ likewise themed “Eleventh Hour” (11.4 million viewers). ABC’s “Desperate Housewives” also did a great job (15.51 million viewers) and was the sixth most viewed show of the week, while the same network’s “Extreme Makeover: Home Edition” lured 11.34 million viewers.

NBC was boosted by Sunday night’s football program (13.1 million viewers) and the premiere of “Kath & Kim” saw a good debut of its own, drawing 7.5 million viewers. Thursday’s special “Saturday Night Live: Weekend Update” also scored big, with 10.85 million viewers, but the network’s new series starring Christian Slater in a double role managed to attract an anemic 7.3 million viewers.

Fox’s most watched program was “The OT,” with 14.2 million viewers, but its numbers were also increased by a Sunday football show.

ABC’ Wednesday night lineup does not look very promising, as neither “Pushing Daisies,” nor “Dirty Sexy Money” managed to surpass the 6 million mark. “Private Practice,” on the other hand, drew a more impressive 7.4 million viewers.

Fox News was the week’s top rated cable network in primetime, with 3.44 million, in spite of the fact that CNN lured more adults under 50 (912,000 compared to 721,000).

The five most watched networks averaged together 37.62 million prime-time viewers last week. However, the figures are not as impressive as they may seem, because the broadcasters lured 42.32 million viewers during the same week last year, according to Nielsen.