NBC’s ”America’s Got Talent” and CBS’ ”Big Brother” tied as the top demo draw on Wednesday, with the former rising and the latter on the decline heading into their upcoming finales.

According to preliminary national estimates from Nielsen, ”Big Brother” kicked off the night for CBS an easy winner (2.8/9 in 18-49, 7.7 million viewers overall), though it was down 15% from last week when the show earned its highest 18-49 rating for any night in four years. The net then aired repeats of ”Criminal Minds” (1.7/5 in 18-49, 6.3 million viewers overall) and ”CSI” (1.1/3 in 18-49, 5.4 million viewers overall), tying NBC for the night in 18-49.

The Peacock again started sluggishly with gameshow ”Minute to Win It” (1.3/4 in 18-49, 5.6 million viewers overall) before spiking at 9 p.m. with ”America’s Got Talent” (2.8/8 in 18-49, 11.8 million viewers overall), up 8% week to week in 18-49 and again the night’s most watched program overall. Also up was the 10 p.m. repeat of ”Law and Order: Special Victims Unit” (1.6/4 in 18-49, 6.3 million viewers overall), which topped its broadcast competition across the board. In addition to tying CBS for the night’s 18-49 lead, NBC also was the outright leader in both adults 25-54 and total viewers.

ABC is picking up viewers for its repeat comedies, as both ”The Middle” (1.2/4 in 18-49, 4.3 million viewers overall at 8 p.m. and 1.5/4 in 18-49, 4.8 million viewers overall at 8:30 p.m.) and ”Modern Family” (1.9/5 in 18-49, 4.9 million viewers overall at 9 p.m. and 1.8/5 in 18-49, 4.4 million viewers overall) grew week to week to their best numbers of the summer. And closing out the night was news series ”Primetime: Nightline” (1.4/4 in 18-49, 4.2 million viewers overall), which was flat week to week and placed second among the broadcasters at 10 p.m. in 18-49 and 25-54.

And Fox’s rookie reality show ”Buried Treasure” was on the rise (1.3/4 in 18-49, 4.2 million viewers overall), though it still lagged its broadcast rivals in the 8 o’clock hour. A repeat followed at 9 (1.2/3 in 18-49, 3.7 million viewers overall).

Preliminary 18-49 averages for the night: CBS and NBC, 1.9/5; Univision, 1.6/4; ABC, 1.5/4; Fox, 1.2/3; CW, 0.5/2.

In total viewers: NBC, 7.9 million; CBS, 6.5 million; ABC, 4.5 million; Fox, 3.9 million; Univision, 3.7 million; CW, 1.3 million.