Despite battling head to head for four months, Fox’s “American Idol” and ABC’s “Modern Family” emerged as the biggest ratings stories of the television season that ends tonight.

In its 10th season, “Idol” may have lost Simon Cowell and moved to a new sked pattern, but it drew more viewers than last season while once again easily ruling as primetime’s No. 1 entertainment series among adults 18-49. And sophomore “Modern Family” continued its quick ascent and emerged as TV’s No. 1 scripted show among young adults — thanks in part to record-setting DVR playback.

Overall, each of the Big Four nets declined year to year.

“Idol” kept Fox on top of the 18-49 demo for a primetime-record seventh consecutive season, while “Family” did its part to lift third-place ABC, whose “Dancing With the Stars” also remains strong.

CBS had the strongest scripted newcomers in a rather blah season for rookies and placed second in 18-49 — beating out both ABC and NBC for a fifth straight year. It also finished a close second to Fox in 25-54 while drawing more viewers than any other network for the eighth time in nine seasons.

And though NBC remained fourth — and struggled especially in the scripted arena — it saw a ray of light in the final month of the season with music competition series “The Voice.”

Univision placed fifth — it was the only broadcaster up vs. last year — and CW ran sixth, with minimal year-to-year losses.

Overall, the Big Four lost more ground to the 100-plus-channel cable universe, down a collective 8% in 18-49 (11.2 vs. 12.2), according to Nielsen data with three nights remaining in the season; basic cable was up 3% in 18-49 (18.4 vs. 17.8).

Looking at the nets, Fox’s move of the “Idol” results show to Thursday shook up advertising’s most important night. Fox grew by 42% vs. last season, dominating the 8 o’clock hour with “Idol” and becoming more competitive at 9 with unsung drama “Bones.”

Soph musical comedy “Glee” slipped some as the season progressed but finished in the top 10 in 18-49 and was the No. 1 scripted skein among the under-35 crowd.

Sunday vet “Family Guy” made the top 15 in 18-49 and was the No. 1 scripted series in men 18-49.

At CBS, eighth-year drama “NCIS” was up vs. last year (when it faced “Idol” on Fox) and finishes as TV’s No. 1 scripted series in 25-54 and total viewers; in its final head-to-head battle with “Glee” last week, the crime drama beat the high-school skein among adults 18-49 for the first time.

Also, “The Big Bang Theory” had a strong first season in its first year on Thursday.

“Two and a Half Men,” despite airing repeats for half the season, still tied with NBC’s “The Office” as TV’s No. 3 sitcom in 18-49. But the lack of originals clearly hurt the net’s Monday lineup, which sagged down the stretch and perhaps kept the Eye from catching Fox for the 25-54 crown.

Though none of the shows were blockbusters, CBS is bringing back three from last fall (“Mike and Molly,” “Hawaii Five-0” and “Blue Bloods”), more than any other network.

ABC was boosted by “Modern Family” (up 23% vs. last year) and its more quiet Wednesday comedy neighbor “The Middle” (up 5%). Also, the spring edition of “Dancing With the Stars” became the show’s most watched to date (likely aided by a lack of firstrun competish from “Two and a Half Men”).

Considering the net lost “Lost” and college football’s championship game, its year-to-year declines aren’t so bad (2% in total viewers, 7% in 18-49). And the Alphabet closed well, moving ahead of CBS for second place in 18-49 for the May sweep.

ABC also aired seven of the top 20 highest-rated regular series among adults earning $100,000-plus, more than any other net.

NBC’s successes came mostly off script, with “Sunday Night Football” dominating its night and “The Voice” emerging as the season’s hottest newcomer (based on its small sample of four airings). Even “The Biggest Loser” and “Celebrity Apprentice,” despite declines, aren’t the net’s problems.

On the other hand, “The Office” was NBC’s only scripted series among the season’s top 30 programs in 18-49 — and that’s where the Peacock needs to improve.

CW grew on Friday (with two scripted hours instead of one a year ago) but fell off on Monday and Thursday, nights that will see new dramas in the fall. “The Vampire Diaries” remains the net’s top draw among the 12-34 set.

Other trends of note:

nRoughly 41% of the homes in Nielsen’s national sample possess at least one DVR, up from 36% in May 2010 and about 30% two years ago. Viewers are increasingly watching on their own timetables, with numerous shows seeing significant spikes from “same-night” ratings to “Live plus 7” ratings, which include full-week DVR playback.

There were seven shows this season that grew by more than 1 full ratings point in adults 18-49 when all DVR play was tabulated, up from four last year. And in total viewers, seven skeins added 2.5 million or more, up from three a year ago.

ABC’s “Modern Family,” in part due to facing “Idol” the second half of the season, set a DVR playback record by averaging a 1.7 ratings gain with its original episodes (from a 4.5 to 6.2) and an overall lift of 3.4 million viewers (11.3 million to 14.7 million).

CBS’ “Hawaii Five-0” was the biggest total-viewer gainer among rookies (11.0 million to 14.3 million).

nBecause DVRs are in such heavy use during the 10 o’clock hour, especially, auds are increasingly shunning the nets’ drama offerings in the hour.

Four seasons ago, there were five 10 o’clock dramas in the season’s top 25 in 18-49; last year there were two (“CSI: Miami” and “The Mentalist”); and in 2010-11, there were none (“Hawaii Five-0” and “Mentalist” came in around No. 30).

nThe strong hourlong class of 2004-05 (the best in memory) lost more ratings steam. One season after “Lost” wrapped, ABC’s “Desperate Housewives” and “Grey’s Anatomy” joined Fox’s “House” in posting declines of 15%-20%.

All three still finished in the top 20 — with “Grey’s Anatomy” again TV’s No. 1 drama in 18-49 — but it’s likely that auds are hungering for new hours to call their faves.

nThe median age of the Big Four moved above 50 for the first time (50.3, vs. 49.8 last year), with CBS (55) and ABC (51.4) the oldest and aging by about one Seasonyear; CW, which targets a younger 18-34 demo, aged by more than a year to 35.

nSpinoffs of NBC’s “Law and Order” and CBS’ “Criminal Minds” failed to live past a first season as fans largely seem happy with their crime/mystery options.

Among the shows gaining young-adult viewers this season were the CBS trio of “NCIS,” “NCIS: Los Angeles” and “Criminal Minds,” ABC’s “Castle” and Fox’s “Bones.” Also, NBC vet “Law and Order: SVU” was down just a bit.

nSports moved to the top of rankings and became more valuable to advertisers as auds watched this programming mostly live.

NBC’s “Sunday Night Football” set records, ranking behind only “Idol” in 18-49 and winning every night it aired. And closing the season, TNT and ESPN had record ratings for NBA playoffs action, topping the broadcasters on some nights.