The World Series and best-since-premiere scores for “The X Factor” powered Fox to an easy primetime ratings victory last week, but the late-October frame also had a fairy-tale flavor to it.

In a fall when no drama had really busted out ratings wise, ABC’s “Once Upon a Time” again impressed in its second outing, retaining nearly all of its aud from one week earlier and standing as the frame’s No. 2 drama among young adults. And another fairy tale-related hour, NBC’s “Grimm,” opened nicely last week too — despite facing the deciding game of the Fall Classic.

“Once” (3.9 rating/9 share in adults 18-49, 11.73 million viewers overall) was the No. 1 entertainment series in its Sunday slot among young adults, according to Nielsen. It retained 98% of its premiere audience in 18-49, 100% in adults 18-34 while growing slightly among teens.

The 18-49 score is especially strong for a second-week rookie drama without strong support. The last two first-year dramas to fare better in the demo with their second segs were CBS’ “NCIS: Los Angeles” (4.1 out of a 4.8 for the original “NCIS” in September 2009) and Fox’s “Lie to Me” (4.4 out of a 10.2 for “American Idol” in January ’09).

For NBC, “Grimm” (2.1/6 in 18-49, 6.56m) posted the strongest 18-49 score for any of the net’s three drama preems of the fall. While not great numbers overall, the demo delivery is the best for a regular Friday series in the 13 months since the debut of “Blue Bloods” on CBS.

It certainly didn’t have much lead-in support, as Friday leadoff hitter “Chuck” opened its final season with weak numbers (1.0/3 in 18-49, 3.42m). If “Grimm” holds up over the next few weeks, NBC may look to shift it to a higher-watched night. Overall last week, Fox rolled to victory in adults 18-49 (3.9/11), followed by CBS (2.8/8), ABC (2.5/7), NBC (2.3/6), Univision (1.4/4) and ESPN (1.0/3). The net also led in adults 25-54 (4.6/11) and total viewers (12.6 million).

Sports claimed the top spots in the program rankings, with NBC’s “Sunday Night Football” game between Dallas and Philadelphia (9.3/22 in 18-49, 22.99m) the top draw in 18-49 rating, though Friday’s Game 7 of the World Series between St. Louis and Texas on Fox (7.4/22, 25.40m) did the same demo share and drew the largest overall audience for any program.

Thursday’s epic, 11-inning game rated third for the week in 18-49 (6.5/18) and drew 21.06 million. The Fall Classic finished with an average aud of 16.6 million viewers, better than last year’s 14.3 million.

Elsewhere, Fox’s “The X Factor” shifted to Tuesday for the second straight week due to the World Series and posted its best scores (4.4/12 in 18-49, 12.09m) in the month since its premiere.

Net’s only other firstrun series aired on Sunday, where the 22nd “Simpsons Treehouse of Horror” (4.0/10 in 18-49, 8.10m) was up over last year; the premiere of animated laffer “Allen Gregory” afterward settled for a 2.4/6 in the demo.

At CBS, Monday’s laffer lineup remained very strong as “Two and a Half Men” (5.5/13 in 18-49, 15.29m) was the frame’s No. 1 scripted show in 18-49. It was joined by top-10 skedmates “2 Broke Girls” (4.5/11, 11.19m), “How I Met Your Mother” (4.3/12, 9.79m) and “Mike & Molly” (4.2/10, 12.16m) as well as “Hawaii Five-0” (3.1/8, 10.70m), the week’s No. 1 10 p.m. drama.

“The Big Bang Theory” (4.6/13, 14.54m) and “NCIS” (4.1/12, 19.43m) remained potent, with the latter ruling as the week’s No. 1 drama in demos and top-rated scripted series of any kind in total viewers. Reality shows “Survivor” (3.5/10, 11.79m) and “Amazing Race” (3.0/7, 11.01m) hit some season highs.

ABC thrived on Wednesday, benefiting from a World Series rainout to deliver series highs for “The Middle” (3.2/10, 10.16m), “Suburgatory” (3.4/10, 9.73m) and “Happy Endings” (3.5/9, 8.33m). “Modern Family” was the night’s No. 1 series in demos despite being in repeat (4.5/12, 11.31m), and 10 p.m. rookie drama “Revenge” was on the rise (2.7/7, 8.72m).

Also edging up last week were “Grey’s Anatomy” (3.7/9, 9.93m) and “Desperate Housewives” (3.1/7, 9.28m), the latter of which is getting a boost from “Once Upon a Time.”

NBC, whose entertainment series were shut out of the week’s top 25 in 18-49, was led by “The Office” (2.9/7, 5.53m).

In cable, it was a down week for “Monday Night Football” (season-low 3.3/8 in 18-49, 7.47m for Baltimore-Jacksonville opposite the World Series). Also, dipping but remaining strong was AMC’s “The Walking Dead” on AMC (3.1/7, 6.10m).

Other standouts included FX dramas “Sons of Anarchy” (2.0/5, 3.82m) and “American Horror Story” (1.7/4, 2.96m) and MTV’s return of “Beavis and Butt-head” (1.8/4, 3.29m).