For Fox, baseball's Red Sox Nation is the all-new Simon Cowell.

The network, which usually spends the fall killing time until the annual January return of Cowell and company on American Idol, rode the Boston Red Sox's playoff run to the top of the latest Nielsen Media Research rankings.

Sunday's American League Championship Game 7, which clinched a World Series berth for Boston's finest over the Cleveland Indians, provided the biggest boost, averaging 19.2 million fans. The contest ranked third among all viewers, and third among car-coveting, flat-screen-desiring 18- to 49-year-olds.

Thursday's Game 5 was a top 20 hit among total viewers (17th place, 13.1 million), and a top 25 hit among young adults.

While the baseball playoffs haven't been a bust for Fox over the years, the 2007 Red Sox have been the biggest boon since, well, since the 2004 Red Sox.

Popular or no, the team's appeal has its limits. Sunday's dramatic game, for the first eight innings anyway, averaged a 71 percent share in Boston, meaning 71 percent of people watching TV that night were watching the Red Sox, compared to "only" a 23 percent share in New York City, home of the Red Sox's archrivals, the Yankees (as well as the Yankees' intracity archrivals, the Mets, whose fans probably accounted for the 23 share).

Manny Ramirez, David Ortiz and the rest of the Boston stars return to Fox's prime-time lineup on Wednesday, via Game 1 of the World Series.

This year's fall classic costars the Colorado Rockies, whose own World Series clinching playoff victory over the Arizona Diamondbacks was observed, on average, by 3.8 million on TBS.

Fox is likely pleased to know it's not relying solely on the strength of Rockies Nation to take down Kid Nation.

Here are the other ratings highlights for the TV week ended Sunday, per Nielsen Media Research stats:

• ABC's Desperate Housewives was back at number one—among 18- to 49-year-olds. Overall, the suburban soap ranked fourth (18.2 million), with CBS' CSI (21.2 million) taking the top spot.
• Christina Applegate's Jesse took heat, and eventually the fall, for losing too many Friends fans. Applegate's new sitcom, Samantha Who? (10th place, 14.4 million), is getting props from ABC for holding on to more of Monday's Dancing with the Stars millions (second place, 19.4 million) than any prior series. The show was the week's highest rated and most watched freshman series. Among half-hour comedies of any age, only NBC's The Office (45th place, 8.6 million) rated higher among 18- to 49-year-olds.
• NBC's Bionic Woman (44th place, 8.6 million) used to be TV's top-rated freshman series. Ah, but we were just kids back then. In September.
• It's not that Wednesday night viewers don't love Jaime Sommers. It's that their parents like CBS' Criminal Minds (ninth place, 15 million) more, and their older sisters need time to decide what to make of the slowly slipping Private Practice (23rd place, 11.8 million) on ABC.        
• Someone had to pay for CBS' Cold Case (24th place, 11.7 million) going cold. And that someone was Viva Laughlin, which premiered on Thursday (47th place, 8.4 million), aired, right before Cold Case, in its regular time slot on Sunday (71st place, 6.4 million) and was canceled on Monday.
• Ratings-wise, Fox's The Next Great American Band (91st place, 3.6 million) is more like the next Celebrity Duets, rather than the next American Idol.
• Having banished Online Nation from Sunday night, the CW celebrated with measurable ratings from an Aliens in America rerun (127th place, 1.3 million).
• Wonder if Aliens in America has enough reruns to cover for the CW's other Sunday night miss, the infotainment show CW Now (144th place, 882,000)?
• Fox's Kitchen Nightmares (66th place, 6.9 million) posted its most watched episode, and got a second-season renewal.
• ABC's Pushing Daisies (34th place, 9.9 million) recorded its least watched episode, and received a full-season pass. 
• About 1 million viewers revoked their membership in ABC's Women's Murder Club (38th place, 9.7 million).
• In cable, Disney Channel's Hannah Montana (5.4 million) was the most watched comedy series; USA's all-new Law & Order: Criminal Intent (4.5 million) was, for a change, significantly bigger than one of its NBC-produced reruns.
• On MySpace, Tila Tequila has more than 1 million friends. On MTV, her new reality show averaged 2.4 million viewers, second only on the network to The Hills (3.3 million).
• AMC's Mad Men closed out its first season the way it started it: with lots of critical raves and not too many viewers (926,000).

Overall, Red Sox-wearing Fox ruled as the most watched network (11.8 million) and the highest rated network in the 18-49 demographic.

CBS slipped to second in total viewers (11 million), and fell to last in the demo. ABC was third in total viewers (10.9 million), and second in desirable ones. NBC ran last in total viewers (8.3 million) and, thanks to a rescue by Heroes (26th place, 11.4 million), third in the demo.

In cable, ESPN was the most watched prime-time network (2.94 million), despite an underwhelming, if top-rated, Monday Night Football performance (8.5 million). Disney Channel (2.93 million) and USA (2.7 million) were close behind.

Here's a look at the 10 most watched broadcast network prime-time shows for the week ended Sunday, according to Nielsen Media Research:

1. CSI, CBS, 21.2 million viewers
2. Dancing with the Stars (Monday), ABC, 19.4 million
3. MLB American League Championship Series Game 7 (Cleveland vs.
Boston), Fox, 19.2 million
4. Desperate Housewives, ABC, 18.2 million
5. Grey's Anatomy, ABC, 18 million
6. NCIS, CBS, 17.6 million
7. Dancing with the Stars (Tuesday), ABC, 17.3 million
8. CSI: Miami, CBS, 15.6 million
9. Criminal Minds, CBS, 15 million
10. Samantha Who?, ABC, 14.4 million