The final week of TV’s summer season produced a couple of rare No. 1 finishes, as Univision moved to the network lead in adults 18-49 while CBS’ “Big Brother” emerged as the top-rated program in the demo.

Spanish-language broadcaster Univision has finished on top a couple of times in the past few years, with its all-firstrun sked faring especially well relative to the Big Four during summer. But for “Brother,” the No. 1 finish in 18-49 was its first in 13 editions.

The voyeuristic reality skein has always been a reliable ratings grabber for the Eye, but its increases this summer have vaulted it up the rankings. According to Nielsen same-night viewing estimates, Wednesday’s hour averaged a big 3.3 rating/11 share in adults 18-49 and 8.34 million viewers overall — besting all primetime programs for the week and notching the show’s top demo score on any night since September 2007.

As the series nears the end of its 13th outing, the three nights of “Brother” are collectively up vs. last year by 12% in 18-49 rating (2.8 vs. 2.5) and by 4% in total viewers (7.5 million vs. 7.2 million).

Overall for the week of Aug. 29-Sept. 4, Univision’s 1.6 rating/5 share in adults 18-49 topped ABC (1.4/4), CBS (1.3/4), and NBC (1.2/4). Fox’s 18-49 rating is believed to be a record low for the net, which also finished behind Univision in total viewers.

CBS tied ABC for the lead among adults 25-54 (1.7/5), while the Eye made it nine straight weeks on top in total viewers (5.6 million).

Univision’s victory in 18-49 was powered by weeknight telenovela “La Fuerza Del Destino” (The Strength of Destiny), which scored a 2.3 rating on both Monday and Wednesday, and by talent show “Pequenos Gigantes” (Little Giants), which built toward its finish with a 1.9 demo rating on both Friday and Sunday.

The net, whose strength is among younger viewers, was even more dominant in adults 18-34 — standing as the No. 1 broadcaster on six of seven nights and beating runner-up ABC by 55% for the week (1.7 rating to 1.1).

Elsewhere, the days leading up to the Labor Day holiday were lightly watched.

Even HBO’s “True Blood” was noticeably below average on Sunday (2.4/8 in 18-49, 4.39m) — though it figures to recoup those viewers in DVR playback — and MTV’s “Jersey Shore” opted for a repeat on Thursday but still scored well enough to crack the top 10 (2.3/7 in 18-49, 4.43m).

NBC’s two-hour Tuesday seg of “America’s Got Talent” ranked second for the week in 18-49 (3.1/9) and first in both 25-54 (3.9/10) and total viewers (10.65 million).

Also showing up in the week’s top five were Monday’s “Hell’s Kitchen” on Fox (2.9/8, 6.21m) and ABC’s season premiere of “Saturday Night Football” (2.7/10, 7.75m for LSU-Oregon). The Alphabet was paced on the entertainment side by “Bachelor Pad” (2./6, 6.48m) and a repeat of “Modern Family” (1.8/5, 4.63m).

Cable highlights included USA prevailing in 18-49, 25-54 and total viewers behind “WWE Raw” (1.8/4, 4.79m) and “Royal Pains” (1.4/4, 5.40m).

MTV finished on top in adults 18-34, getting nice boosts from the Monday preem of viral video series “Ridiculousness” (1.5/4, 3.14m), whose 2.2/7 in 18-34 led cable for the night.

ABC’s “Pretty Little Liars” wrapped the first half of its second season with its second best scores of the summer (1.2/4, 2.98m), racking up an impressive 3.9/13 in females 12-34.

And VH1 successfully extended its “Basketball Wives” franchise to “Basketball Wives: L.A.,” whose preem on Monday drew about 1.8 million viewers (and 3 million if you add in its same-night repeat).