CBS was television’s most popular network last week, but that status is no longer the slam-dunk that it has been for the last decade and a half.

It was CBS’ second weekly victory of the young television season, matching NBC’s two victories, the Nielsen company said Tuesday. NBC handily won among viewers aged 18 to 49, the demographic group that it cares the most about.

Sunday night football gives NBC a big boost in the fall, but series like “This Is Us,” ‘’Manifest” and Dick Wolf’s “Chicago” dramas make the network more competitive with scripted series than it has been in the past.

The premiere of ABC’s Roseanne-less sitcom “The Conners” reached more than 10.5 million viewers last week, and it was the most popular scripted series of the week among the youthful demographic. It will likely get fewer viewers this week; how big the drop is will be an important clue about the series’ long-term prospects.

For the week, CBS averaged 7.6 million viewers in prime time. NBC had 7.2 million viewers, ABC had 4.7 million, Fox had 4.3 million, Telemundo had 1.3 million, ION Television and Univision were tied with a 1.2 million viewer average and the CW had 1.1 million.

TBS was the week’s most popular cable network with the help of baseball playoffs, averaging 2.69 million viewers in primetime. ESPN had 2.57 million, Fox News Channel had 2.54 million, MSNBC had 1.43 million and TNT had 1.41 million.

ABC’s “World News Tonight” topped the evening newscasts with an average of 8 million viewers, NBC’s “Nightly News” had 7.8 million and the “CBS Evening News” had 5.8 million.

Below are primetime viewership numbers compiled by Nielsen for Oct. 15-21. Listings include the week’s ranking and viewership.

1. NFL Football: Cincinnati at Kansas City, NBC, 16.02 million.
2. “60 Minutes,” CBS, 14.07 million.
3. “The Big Bang Theory,” CBS, 12.23 million.
4. NFL Football: San Francisco at Green Bay, ESPN, 12.17 million.
5. “NCIS,” CBS, 11.87 million.
6. “Sunday Night NFL Pre-Kick,” NBC, 11.3 million.
7. “Young Sheldon,” CBS, 11 million.
8. “The Conners,” ABC, 10.57 million.
9. “The Voice” (Monday), NBC, 9.99 million.
10. “FBI,” CBS, 9.31 million.
11. NFL Football: Denver at Arizona, Fox, 9.13 million.
12. “The Voice” (Tuesday), NBC, 8.99 million.
13. “This Is Us,” NBC, 8.93 million.
14. “God Friended Me,” CBS, 8.86 million.
15. “Football Night in America,” NBC, 8.85 million.
16. “Blue Bloods,” CBS, 8.46 million.
17. “NCIS: Los Angeles,” CBS, 8.35 million.
18. “Mom,” CBS, 8.13 million.
19. “Chicago Fire,” NBC, 7.88 million.
20. “Chicago Med,” NBC, 7.74 million.

ABC and ESPN are owned by The Walt Disney Co.; CBS is a division of CBS Corp.; Fox is owned by 21st Century Fox; NBC is owned by NBC Universal.