Big Brother” was the dominant program in key demos on Sunday, teaming with a rising “Unforgettable” to lift the net to victory in key demos. Meanwhile, whatever momentum ABC’s “Rising Star” seemed to have last week when it posted gains amid an all-around improved night for the network has been dashed as the singing competition dropped to its lowest scores to date.

According to preliminary national estimates from Nielsen, CBS followed “60 Minutes” (0.9/4 in 18-49, 7.7 million viewers overall), the night’s most-watched program overall, with “Big Brother” (2.1/8 in 18-49, 6.4 million viewers overall), the leader in 18-49 and 25-54 (2.4/7). While “Big Brother” was down a smidge from last week, 9 p.m. drama “Unforgettable” (1.0/3 in 18-49, 6.4 million viewers overall) was up a tick for its best score in four airings this summer; it has picked up in the two weeks since it moved from 10 to 9. Capping the night for CBS, firstrun drama “Reckless” (0.6/2 in 18-49, 4.1 million viewers overall) was also up a tenth in the demo while gaining about 150,000 total viewers; this matches the show’s top 18-49 score to date and is its largest overall audience.

ABC, whose lineup one week ago benefited from the network’s late-afternoon coverage of the World Cup final, came back to earth last night. Following a repeat of “America’s Funniest Home Videos” (0.9/4 in 18-49, 4.8 million viewers overall), “Wipeout” (1.0/4 in 18-49, 3.8 million viewers overall) fell off four tenths from its week-ago season high. And after posting its first week-over-week gain to date last week (going from a 1.2 to 1.3), “Rising Star” (1.0/3 in 18-49, 4.1 million viewers overall) was down three tenths to its low. It did hit a high in kids 2-11 (381,000), a demo that made up more than 9% of its audience.

Fox aired encores of “American Dad” (0.4/2 in 18-49, 1.1 million viewers overall), “Bob’s Burgers” (0.6/2 in 18-49, 1.4 million viewers overall), “The Simpsons” at both 8 (0.9/3 in 18-49, 2.1 million viewers overall) and 8:30 (1.1/4 in 18-49, 2.5 million viewers overall), “Family Guy” (1.5/5 in 18-49, 3.1 million viewers overall) and another “American Dad” (1.4/4 in 18-49, 2.9 million viewers overall). “Family Guy” was the night’s No. 1 broadcast in adults 18-34 (1.5/6) as well as both men 18-34 (1.7/8) and men 18-49 (1.8/6).

And NBC went with repeats of “American Ninja Warrior” (0.9/3 in 18-49, 3.1 million viewers overall), “Law & Order: SVU” (0.7/2 in 18-49, 2.6 million viewers overall) and “Chicago PD” (0.6/2 in 18-49, 2.8 million viewers overall).

Preliminary 18-49 averages for the night: CBS, 1.1/4; Fox, 1.0/4; ABC, 0.9/3; NBC, 0.8/3; Univision, 0.6/2; Telemundo, 0.4/1.

In total viewers: CBS, 6.1 million; ABC, 4.1 million; NBC, 2.9 million; Fox, 2.2 million; Univision, 1.9 million; Telemundo, 0.8 million.