Though ABC and CBS have gotten most of the headlines this fall, NBC has quietly put pieces together.

Sure, the new Sunday night NFL package is responsible for much of its ratings growth, but the net’s Monday drama “Heroes” is the hottest rookie this fall, and gameshow “Deal or No Deal” still sizzles.

So while the Peacock may be hard-pressed to finish above fourth place for the season, it has some real momentum going for the first time in years.

Through the first 10 weeks of the season, NBC was averaging a third-place 3.7 rating among adults 18-49, up 16% vs. last season, according to Nielsen estimates.

It has closed the gap with leaders ABC (4.2) and CBS (3.9) while opening up some distance on fourth-place Fox (3.0), which is expected to make its annual rise from the ashes when “American Idol” returns in January.

Looking deeper into the numbers, though, NBC has done a good job of capitalizing on the young, male aud it’s gotten for football on Sundays.

Net ranks a close No. 2 to Fox in men 18-34 (2.9 to 3.0) and is second in adults 18-34 to ABC (3.1 to 3.4), rising a sharp 19% year to year.

Looking younger

It has also lowered its median age by more than two years. Half of its aud is 47 years or older, making it younger than ABC (47.5) for the first time in a few years and nearly five years younger than CBS (51.9).

This is key, as the net that relied too heavily on “Dateline” and the “Law & Order” franchise in recent years seems to be zeroing in on programs specifically for an 18-49 aud.

“Heroes” has been the standout, averaging a 6.5 rating to become the top new program on any net in the past two seasons. It has especially struck a chord among young men, but it’s no slouch among women, averaging a similar 6.4 rating among femmes 18-34.

Tapping into a younger aud are Thursday’s “My Name Is Earl” and “The Office” — perhaps the strongest comedy hour on television.

What the net needs above all else is another hot laffer. If it can find one in the next 18 months (assuming “Scrubs” is around for another season in the key 9 o’clock slot), it might position itself to recapture Thursday in a few years.

NBC also has other new dramas that have garnered critical acclaim but smallish auds.

“Friday Night Lights,” among the best dramas, has averaged a 2.5 rating in adults 18-49 and 18-34 in a tough slot.

“Studio 60” has averaged a 3.8 rating in 18-49, but has not topped a 3.3 rating since October. The success of “Deal” and “Heroes” on the night, though, affords the net the luxury of keeping “Studio” around a while.

Looking at the November sweep (Nov. 2-29), NBC’s 3.8 average in adults 18-49 was up 15% vs. last year, tying the net with CBS for second, with the Eye down 14%. The Peacock was the only net to gain vs. last November, and this was its best season-to-season growth for a November sweep in at least 20 years.

ABC finished on top with a 4.1 rating, down 7% from last year, when it had a huge month with “Monday Night Football.”

CBS, with its lineup heavy on regularly skedded series, finished first in adults 25-54 for a fourth straight November. But it was slow going for Fox, as its distant fourth-place average (3.0) was down 7% from last year.

Newbie CW finished with a 1.5, on par with the WB last year. Net picked up some steam, though, notching its best numbers of the season on the final Sunday, Monday and Tuesday of the ratings period.