ABC’s special preview of its new relationship drama “What About Brian” won its 10 p.m. (ET) time period Sunday night but lost more than one-third of the time period’s usual adults 18 to 49 audience.

“Brian” scored a 5.6 preliminary national rating in the demo, a number that includes live-plus-same-day viewing, according to Nielsen Media Research. That was second for the night in adults 18 to 49 only to its lead-in, “Desperate Housewives,” (7.7) but down 5 percent from the previous week’s repeat of “Grey’s Anatomy” in the time period.

“Brian” was down 22 percent from”Grey’s” midseason debut last year and down 36 percent from “Grey’s” season-to-date average in the demo. “Brian” also dropped from a 6.0 in its first half-hour to a 5.1 in its second half-hour.

ABC was still the dominant network for the night, scoring a 5.1 in adults 18 to 49, almost double its next closest competitor, NBC (2.7).

“Brian” debuts in its regular time period Monday, April 17, at 10 p.m.