A strong premiere from the new Tim Allen series "Last Man Standing" was just not enough for ABC to take over the top spot in the weekly ratings race as CBS captured its fifth straight weekly crown.

"Last Man Standing" debuted to an 8.1 rating/12 share in Fast National overnight ratings from The Nielsen Co., yet ABC finished slightly lower than its numbers from a year ago, finishing the week with a 6.7/10 average behind a 7.4.11 from CBS. The show did 62 percent better than its timeslot from a year ago, and 23 percent better than what "Dancing With the Stars" was doing in the timeslot.

But then again, the question becomes how well the show will hold on to its audience. Another new ABC show, "Revenge," has not been pulling in amazing ratings, and has already suffered some audience erosion. The primetime soap earned a 5.3/9 this week, but has an Audience Loyalty Index rating of 85.4 -- the lowest of this week's top 10 new shows. That means of all the people who have tuned in to see at least one episode of "Revenge," only 85 percent are coming back this week.

Another ABC show, "Pan Am," has suffered through an ALI of 76.9, and is in danger of an early flight cancellation. The newly cancelled "Charlie's Angels" retained about 80 percent of its audience from week to week.

It's not all bad news for ABC's new shows, however. "Suburgatory" is pulling in a 5.5/9, but it's still finishing in the top 10 new shows, and has an ALI of 93.0, meaning that 93 percent of the show's largest audience is coming back each and every week, a strong audience retention. ABC will have to wait and see how "Last Man Standing" does this week before deciding whether it will be an out-of-park success, or simply good news for a weak slate of new shows so far.

For CBS, network television's top-rated scripted show, "NCIS," matched its season high with an 11.9/18. Right now, that series is drawing an audience more than 4 percent larger than it did last year. "Two and a Half Men," with new star Ashton Kutcher, has dropped considerably from its unusually high premiere, but it is still going strong. It earned a 9.5/13 this week, dropping its average to a 12.0/17. Yet it's still 60 percent better than CBS did in the timeslot last year, despite falling 41 percent from its premiere.

Even with limited outings of "The X Factor," Fox is still having its strongest fall season in a long time. Its 4.6 household rating is 18 percent better than it was this time last year, but is still deep in third place, far behind CBS and ABC. It does remain ahead of NBC, which has fallen 8 percent year over year.

Top Networks, Week of Oct. 9 -- [Audience Loyalty Index rating]

Top Network Shows, Week of Oct. 9 -- [ALI]

Top New Shows, Week of Oct. 9 -- [ALI]

Bottom Big Four Network Shows, Week of Oct. 9 -- [ALI]

Fast Nationals usually provide a snapshot of what Americans are watching by pulling numbers from the top urban markets that include both live viewing and same-day timeshifted viewing. A rating point generally represents more than 1.1 million households while the share indicates the percentage of televisions turned on that was tuned to the specific program. These numbers typically shift when final ratings are issued.

Data collected from The Nielsen Co., as distributed by Zap2it. GenreNexus tracks non-news, non-event programming, and figures for this story reflect airing of new episodes only. For more information on the Audience Loyalty Index, click here.