A show that has been one of the bright spots for NBC reached a historic low in the ratings Tuesday night, based on Nielsen overnights for the key 18-49 demo.

TVbytheNumbers.com reports that “The Voice” registered a 2.7 average in viewers 18-49, losing 13% from a week ago and setting an all-time series low. Leading out from “The Voice” at 9 p.m., the network’s two-hour “America’s Got Talent” was also down, falling 3% from last week to a 3.0.

Meanwhile, ABC rolled to a win for the night on the strength of the NBA Finals, even though game three was down 13% from last year. The game, in which the San Antonio Spurs blew out the Miami Heat by 36 points, delivered a 4.9 average in the 18-49 demo.

ABC’s warmup shows had mixed results. “Jimmy Kimmel Live — Game Night” was up 26% from last year to a 2.4 average in 18-49, while “NBA Countdown” dipped 12% to a 2.3.

Fox saw its “So You Think You Can Dance” lose ground, with the two-hour show falling 14% from a week ago to a 1.6 average rating in adults 18-49.

CBS followed repeats of “NCIS” (1.1 average in 18-49) and “NCIS: Los Angeles” (1.0) with its only fresh show of the night, “Brooklyn DA,” which lost 14% from last week’s premiere to notch a 0.6 average.

For prime time overall, ABC’s 4.0 average led the way in the 18-49 demo, followed by NBC (2.9 average), Fox (1.6), Univision (1.1) and CBS (0.9). NBC pulled ahead in total viewers, averaging 11.1 million to 10.0 million for ABC, 6.5 million for CBS, 4.2 million for Fox and 3.0 million for Univision.