Post-“Dancing with the Stars,” ABC’s Tuesday lineup seems to be in serious trouble. Last night the premiere of the new wedding-themed sitcom “Big Day” delivered disappointing numbers despite a strong lead-in from “Charlie Brown Christmas.”

“Day” averaged a 2.8 adults 18-49 rating in the 9 p.m. timeslot, according to Nielsen overnights, losing 42 percent of “Charlie’s” 4.8 lead-in. In households it averaged a 4.6 rating, more than a point behind third-place "Law & Order: Criminal Intent" on NBC.

What’s more, the new sitcom “Help Me Help You,” which had been averaging a so-so 3.1 18-49 rating behind “Stars,” dipped to a series-low 1.8 behind “Day.” The two sitcoms combined for a 2.3 average, fourth in the timeslot and less than a point ahead of “Veronica Mars” on the CW.

ABC finished third for the night, behind Fox and CBS, with a 3.4 average, a full 1.1 behind its season-to-date “Stars”-fueled Tuesday average.

No one expected the network to maintain that level without “Stars,” of course, but a 2.3 combined average for the sitcoms is alarming. “Help” dipped below what NBC’s “Twenty Good Years” averaged before it was yanked earlier this year, and “Day” was right around the average for several sitcoms ABC canceled last year.

On the strength of “House,” Fox was first for the night among viewers 18-49 with a 4.6 average rating and 12 share. NBC finished second at 3.6/9, ABC third at 3.4/9, CBS fourth at 3.3/9, CW fifth at 1.9/5 and Univision sixth at 1.6/4.
 
ABC led at 8 p.m. with a 4.8 average for “Charlie.” CBS was second with a 4.1 for “NCIS,” NBC third with a 2.4 for “Friday Night Lights” and Fox fourth with a 2.3 for “Standoff.” That left CW and Univision in a tie for fifth at 2.2, CW for “Gilmore Girls,” hitting a season high, and Univision for “La Fea Mas Bella.”
 
Fox took the lead at 9 p.m. with its 6.8 for “House,” easily the top-rated show of the night among 18-49s. CBS was second that hour with a 3.4 for “The Unit,” NBC third with a 3.1 for “Law & Order: Criminal Intent” and ABC fourth with a 2.3 average for “Day” (2.8) and “Help” (1.8). CW remained fifth that hour with a 1.6 for “Veronica Mars,” which tied its highest-rated episode ever, and Univision fell to sixth with a 1.5 for “Mundo de Fieras.”
 
It was NBC’s turn on top during the 10 p.m. hour, as the network led with a 5.2 for “Law & Order: SVU.” ABC was second with a 3.0 for “Boston Legal,” CBS third with a 2.4 for “3 Lbs.” and Univision fourth with a 1.1 for the special “Lo que No Vio de ‘Premios TV y Novelas.’”
 
CBS didn’t lead any hour among 18-49s, but it took the night among households with an 8.1 average rating and a 13 share. Fox was second at 7.1/11, NBC third at 6.8/11, ABC fourth at 5.8/9, CW fifth at 2.6/4 and Univision sixth at 2.1/3.