Matt Lauer’s much-hyped chat with Prince Harry and Prince William, the first in which they spoke about their late mother, drew big ratings for NBC last night.

The special “Dateline” averaged a 4.1 rating in adults 18-49, according to Nielsen overnights, finishing No. 1 for the night in the demographic and dominating the 10 p.m. timeslot.

The show averaged 12.2 million total viewers, making it the most-watched newsmagazine of the summer and the most-watched non-sports program on broadcast since Fox’s “House” season ender last month.

It was the top-rated “Dateline” since a January 2005 episode with an interview of Amber Fry. It scored NBC’s best numbers in the 10 p.m. Monday slot since the Golden Globes some five months ago.

Portions of the interview aired yesterday morning on “Today,” and NBC had been hyping the special for days. It marked the princes’ first interview with an American journalist, as well as the first time they’ve talked publicly about their late mother, Diana, since her death in a car crash 10 years ago.

They agreed to do the interview largely to hype a July 1 charity concert for Princess Diana, on what would have been her 46th birthday. NBC is airing a special with portions of the event that night.

The interview helped boost NBC to first for the night among viewers 18-49 with a 3.2 average overnight rating and a 9 share. Fox was second at 2.5/8, CBS third at 2.2/7, ABC fourth at 1.8/5, Univision fifth at 1.7/5 and CW sixth at 0.7/2.
 
At 8 p.m. NBC started the night in the lead with a 3.1 for “Deal or No Deal,” followed by ABC with a 2.3 for a repeat of “Wife Swap.” Univision was third that hour with a 1.8 average for “La Fea Mas Bella” (1.9) and “Yo Amo a Juan Querendon” (1.6), with Fox fourth with a 1.7 for repeats of “The Simpsons” and “American Dad,” CBS fifth with a 1.4 for “Creature Comforts” (1.3) and a repeat of “The New Adventures of Old Christine” and CW sixth with a 0.7 for repeats of “Everybody Hates Chris” and “All of Us.”
 
At 9 p.m. Fox led with a 3.4 for “Hell’s Kitchen,” with CBS second with a 2.6 for repeats of “Two and a Half Men” and “How I Met Your Mother.” NBC was third with a 2.4 for the series debut of “Age of Love,” Univision fourth with a 1.9 for “Destilando Amor,” ABC fifth with a 1.4 for “Ex-Wives Club” and CW sixth with a 0.7 for repeats of “Girlfriends” and “The Game.”
 
NBC regained the lead in a big way at 10 p.m., posting a 4.1 for “Dateline.” CBS was second with a 2.8 for a repeat of “CSI: Miami,” with ABC and Univision tied for third at 1.6, ABC for a repeat of “Supernanny” and Univision for “Cristina.”
 
Among households, NBC was first for the night with a 7.0 average rating and a 12 share. CBS was second at 4.8/8, ABC third at 3.3/6, Fox fourth at 3.2/5, Univision fifth at 2.1/4 and CW sixth at 1.2/2.