A pair of ”The Big Bang Theory” repeats topped the ratings chart on Thursday for CBS, lifting the net to victory over mostly original competition on rival nets. Fox’s ”Take Me Out” and ”The Choice” joined ABC’s ”Rookie Blue” in showing week-to-week gains.

According to preliminary national estimates from Nielsen, ”The Big Bang Theory” averaged a 2.1 rating/8 share in adults 18-49 and 8.1 million viewers overall in its regular 8 p.m. slot and then built at 8:30 p.m. to a 2.4/8 in the demo and 8.9 million viewers overall, making it the night’s No. 1 program in both categories. The comedy was followed by reruns of crime dramas ”Person of Interest” (1.5/5 in 18-49, 8.0 million viewers overall) and ”The Mentalist” (1.2/4 in 18-49, 6.8 million viewers overall).

Beginning next Thursday, ”Big Brother” will air in the 9 p.m. hour for CBS, with ”Person of Interest” sliding to 10 p.m. for the rest of summer.

Elsewhere Thursday, Fox’s first-year dating competition series ”Take Me Out” (1.3/4 in 18-49, 3.1 million viewers overall) and ”The Choice” (1.6/5 in 18-49, 3.8 million viewers overall) both shot up nicely week to week, with the former posting its best score yet in adults 18-34 (1.2/5). ”The Choice,” perhaps boosted by celebrity contestant Rob Kardashian, was Thursday’s No. 1 broadcast in women 18-34 (2.1/7).

ABC continues to struggle with ”Duets” (1.0/3 in 18-49, 4.8 million viewers overall), though it drew its largest overall audience in a month. From there, the net saw ”Wipeout” (1.7/5 in 18-49, 5.5 million viewers overall) decline about 15% from its week-ago premiere but it narrowly led its hour in 18-49. And at 10, ”Rookie Blue” (1.3/4 in 18-49, 5.1 million viewers overall) rebounded from its low of last week to top both CBS and NBC for the hour among adults 18-49.

At NBC, there is no saving ”Saving Hope” (0.4/1 in 18-49, 2.2 million viewers overall), with the rookie 9 p.m. drama drawing its lowest score to date. Also for the net, repeats of ”The Office” (0.6/2 in 18-49, 2.1 million viewers overall) and ”Parks and Recreation” (0.6/2 in 18-49, 1.5 million viewers overall) didn’t do much in the night’s opening hour, and ”Rock Center with Brian Williams” was up slightly week to week at 10 (0.9/3 in 18-49, 3.3 million viewers overall). This is the best score of the summer for ”Rock Center,” though it ran fourth among the broadcasters in 18-49 and 25-54.

Univision led all broadcasters at 10 p.m. with ”La Que No Podia Amar” (1.5/4 in 18-49, 3.9 million viewers overall). The net tied with ABC for third on the night in 18-49.

CW saw a slight bump for the finale of ballet series ”Breaking Pointe” (0.3/1 in 18-49, 0.9 million viewers overall).

Preliminary 18-49 averages for the night: CBS, 1.7/5; Fox, 1.4/5; ABC and Univision, 1.3/4; NBC, 0.6/2; CW, 0.3/1.

In total viewers: CBS, 7.8 million; ABC, 5.2 million; Univision, 3.5 million; Fox, 3.4 million; NBC, 2.4 million; CW, 0.7 million.