NBC won Tuesday in key demos behind the night's top two broadcasts, "America's Got Talent" and new drama "The Night Shift," the latter of which held up well in its second week. Also of note was a nice finish for ABC's "Celebrity Wife Swap" and a quiet start for CW's "Famous in 12."

According to preliminary national estimates from Nielsen, "America's Got Talent" averaged a 2.8 rating/10 share in adults 18-49 and 11.2 million viewers overall from 8 to 10 p.m., down 7% (0.2) from last week's season premiere but easily Tuesday's top-rated program by all measures; it was also down 7% from last year's second episode, though that aired from 9 to 11 p.m. and followed a lead-in from "The Voice."

Medical drama "The Night Shift" (1.5/5 in 18-49, 7.2 million viewers overall) declined just 6% (0.1) from last week's premiere, which had rated as one of the best drama launches on the Big Four in recent years. It won over ABC and CBS in all key categories.

At ABC, "Extreme Weight Loss" (1.1/4 in 18-49, 3.9 million viewers overall) was down two-tenths from last week's premiere (though it should rise to a 1.2 in the nationals), again performing slightly better than the comparable episode of last year. Building on its lead-in at 10 p.m. was the season finale of "Celebrity Wife Swap" (1.4/5 in 18-49, 4.0 million viewers overall), which grew 17% (0.2) week to week as it featured David Justice and Dweezil Zappa trading lives.

At CW, unscripted series/social experiment "Famous in 12" opened to a mere 0.3/1 in 18-49 and about 700,000 viewers -- only a smidge better than last week's repeat of "The Originals." A repeat "Supernatural" followed at 9 (0.3/1 in 18-49, 0.7 million viewers overall).

Fox continues to flounder on Tuesdays this early summer with its new alternative series "Riot" (0.4/2 in 18-49, 1.2 million viewers overall) and "I Wanna Marry Harry" (0.4/1 in 18-49, 1.0 million viewers overall) -- drawing less than half the young-adult audience of repeats of the "NCIS" series airing in the same time periods on CBS. "Riot" was down two-tenths from last week, and "Harry" held steady.

CBS aired encores of crime dramas "NCIS" (1.0/4 in 18-49, 8.6 million viewers overall), "NCIS: Los Angeles" (1.0/3 in 18-49, 7.6 million viewers overall) and "Person of Interest" (0.8/3 in 18-49, 5.7 million viewers overall).

Preliminary 18-49 averages for the night: NBC, 2.4/8; ABC, 1.2/4; CBS, 1.0/3; Univision, 0.9/3; Telemundo, 0.6/2; Fox, 0.4/1; CW, 0.3/1.

In total viewers: NBC, 9.8 million; CBS, 7.3 million; ABC, 3.9 million; Univision, 2.5 million; Telemundo, 1.5 million; Fox, 1.1 million; CW, 0.7 million.

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