HOLLYWOOD — The Super Bowl has put ABC back in the ratings game, while “American Idol” has formerly feeble Fox singing a happy tune.

Both nets, which have taken a back seat this season to leaders NBC and CBS, are now in the hunt for what figures to be a competitive battle in the key adults 18-49 demo chase.

And while ABC has at least temporarily moved ahead of CBS into second place for the season in adults 18-49, it’s Fox that appears to have the momentum and the best shot at the silver. Net last week, behind 3½ hours of “American Idol” and another big “Joe Millionaire,” delivered the highest weekly average without sports help for any net this season (5.6/13).

Still, the Alphabet web dominated the week of Jan. 20-26, according to Nielsen, sweeping the frame’s key ratings across the board with its best averages since the last time it carried the Super Bowl in 2000. Net topped Fox by 12 shares in men 18-49 and by 7 shares in women 18-49.

The matchup between the Tampa Bay Buccaneers and Oakland Raiders in “Super Bowl XXXVII” produced the largest aud for the big game in five years (88.64 million) and its best adults 18-49 rating in three years (36.4/70).

With both the longest Super Bowl and postgame show in at least 15 years, football covered the entirety of primetime for ABC on Sunday. And while that helped boost the net’s averages on the night — it’s the most-watched night of primetime programming on any net in seven years — it didn’t help second-year drama “Alias,” which had to wait until roughly 11 p.m. in the East before it hit the air.

Small by post-Bowl standards, “Alias” did draw its best numbers to date (17.4m, 8.2/23 in A18-49). Spy skein now looks to build off this momentum in upcoming weeks.

ABC’s other highlights for the week included solid second-place finishes on Wednesday for “The Bachelorette” (6.0/14 in adults 18-49) and “Celebrity Mole” (5.0/13), the best 18-49 score in 18 months for Friday’s “America’s Funniest Home Videos” (3.9/12) and its strongest nonsports Thursday of the season, thanks to repeats of comedies and season highs for newsmag “Primetime” (5.1/12 in A18-49, 12.66m).

“American Idol” on Tuesday became Fox’s fourth-highest-rated 18-49 season or series premiere in its history, with its 12.4/30 trailing only “The X-Files” in 1997 (15.7/30), “Married … With Children” in 1991 (15.5/36) and “The Simpsons” in 1990 (15.3/39).

Fox’s big Tuesday night, which included the 30-minute spec “American Idol Revisited,” marked the network’s highest-rated night ever among adults 18-49 (excluding its three Super Bowls). Overall, it was the net’s best nonsports week in four years among adults 18-49 and five years among total viewers.

NBC didn’t have the fireworks of either ABC or Fox but still delivered 10 of the week’s top 20 programs among adults 18-49, more than the next two nets combined (Fox with five and ABC with four) and placed third in most key categories.

Reality skein “Meet My Folks” did well in two special previews on Monday (6.7/16 in A18-49) and Tuesday (5.6/14) before moving to its regular Saturday-at-10 slot, where its 3.6/11 in the demo won the hour by 29%. Net was also pleased with Thursday comedies “Scrubs” and “Good Morning Miami,” which retained the biggest chunks of their (albeit repeat) lead-ins this season.

At CBS, “Star Search” held up very well on Wednesday despite competish from “American Idol” and then hit a new 18-49 high with its Thursday seg (4.8/12). And the net’s repeat of “CSI” (8.4/20 in A18-49, 24.46m) was the week’s top-rated scripted program.

On the down side, the net’s first-year dramas “Presidio Med” and “Queens Supreme” finished last in their slots among the major nets and have since been effectively canceled.

The WB saw its femme-focused dramas “Gilmore Girls” and “Dawson’s Creek” take a hit opposite “American Idol,” but the net continues to perform well ahead of last year.

UPN’s “WWE Smackdown” grabbed its best ratings since October among men 18-34 (3.8/11) and adults 18-34 (3.0/8), while movie “Ace Ventura: When Nature Calls” gave the net its best Friday of the season in adults 18-49 (1.3/4) and 18-34 (1.7/6). On the series front, though, new laffer “Abby” drew a miniscule 1.02 million viewers on Tuesday — placing 17th in its 9 o’clock slot, behind the five broadcasters and 11 cablers.

USA, TNT and TBS tied for the week’s basic-cable lead among adults 18-49, with each drawing a 0.7 rating in the demo. TLC’s “Trading Spaces” was the week’s top show in 18-49 (2.8/9), placing second to Fox’s “America’s Most Wanted” in its Saturday-at-9 slot.

Nickelodeon was the most-watched cabler in primetime (2.13 million), followed by TNT (1.96m), Lifetime (1.90m) and USA (1.89m).