Sunday night's Grammy Awards dominated primetime, but the telecast fell to its lowest ratings with adults 18-49 since at least 1992.

The three-hour telecast averaged 18.2 million viewers and a 6.9 rating/16 share in the adults 18-49 demographic, according to preliminary estimates. That's the third-lowest viewership since Nielsen began electronic monitoring, as well.

Most of the other networks were in repeats against the Grammys, although ABC saw some success earlier in the night with "America's Funniest Home Videos" (9.6 million, 3.0/8) and "Extreme Makeover: Home Edition" (15.7 million, 5.4/12). But everyone else had a rough time including a one-hour repeat "Family Guy" (6.9 million, 3.3/7), an original ABC's "Brothers & Sisters" (8.6 million, 3.1/8) and the entire CW schedule. "Brothers & Sisters" fell to its lowest original rating in its two-year history.

CBS (16.9 million, 5.8/14) led the night in viewership and 18-49 over ABC (12.4 million, 4.3/10); NBC (5.9 million, 2.1/5); Fox (7.4 million, 3.2/8); and The CW (951,000, 0.3/1).