April is a tough month to launch a new series, and while there weren’t a lot of sparks generated by Thursday’s two premieres, CBS’ “Bad Teacher” got off to a solid-enough start while ABC’s “Black Box” posted decent numbers — especially considering the disastrous results for the net’s other 10 p.m. drama bows this season (“Lucky 7,” “Killer Women,” “The Assets” and “Mind Games”).

According to preliminary national estimates from Nielsen, CBS won the night in key demos behind “The Big Bang Theory” (4.3 rating/16 share in adults 18-49, 16.0 million viewers overall), easily Thursday’s No. 1 program in all categories though down about 10% from its prior original. It was followed by “The Millers” (2.5/8 in 18-49, 10.1 million viewers overall) and “Two and a Half Men” (2.5/8 in 18-49, 9.5 million viewers overall), both of which led their half-hours, and then the series premiere of “Bad Teacher” at 9:30 (2.1/6 in 18-49, 7.9 million viewers overall). “Teacher” placed second in its timeslot in 18-49, up 62% from last week’s season finale of “The Crazy Ones” (1.3) and the best performance for the net in the timeslot since early January. “Elementary” closed the night (1.6/5 in 18-49, 8.1 million viewers overall), matching the 18-49 score of its prior original and edging out ABC’s “Black Box.”

For ABC, “Black Box” (1.5/4 in 18-49, 6.6 million viewers overall) retained 65% of its “Grey’s Anatomy” lead-in (2.3/7 in 18-49, 7.6 million viewers overall) and placed second among series in the 10 o’clock hour. While not great numbers, “Black Box” more than doubled the weak 0.7 demo rating generated in January by the premiere of “The Assets” (which didn’t have a “Grey’s” lead-in) and drew the largest overall audience for a 10 p.m. ABC drama premiere (on any night) since “Nashville” in October 2012.  As expected, “Black Box” couldn’t come close to this season’s time period average of “Scandal” (3.0 in 18-49), which wrapped its season early due to the pregnancy of star Kerry Washington.

ABC started the night off with its lowest-rated showing of the season in the Thursday 8 p.m. hour courtesy of a special repeat of last Thursday’s latenight “Jimmy Kimmel Live” episode devoted to the season finale of “Scandal” (0.6/2 in 18-49, 2.8 million viewers overall); it appears that just about anyone interested tuned in last week as that special Thursday episode drew the 11-year-old show’s largest audience to date (over 4 million). “Kimmel” led into “Grey’s,” which was down about 12% (0.3) week to week to match its low, but tied with CBS for the hour’s 18-49 lead.

At Fox, “Hell’s Kitchen” (1.7/6 in 18-49, 4.8 million viewers overall) matched last week’s score and placed second for its hour. From 9 to 10, “American Idol” edged up a tick (1.8/5 in 18-49, 7.6 million viewers overall) while “Surviving Jack” held steady (1.0/3 in 18-49, 3.9 million viewers overall).

NBC’s hourlong season finale of “Parks and Recreation” (1.0/3 in 18-49, 2.7 million viewers overall) was up 11% (0.1) from last week’s half-hour episode. From 9 to 11 p.m., the net didn’t do much with its two-hour “SNL Shorts” special (1.0/3 in 18-49, 2.5 million viewers overall) .

CW’s “The Vampire Diaries” (0.7/3 in 18-49, 1.8 million viewers overall) and “Reign” (0.5/1 in 18-49, 1.4 million viewers overall) bounced back from their lows of last week, with the latter up 67% (0.5 vs. 0.3) in women 18-34.

Preliminary 18-49 averages for the night: CBS, 2.4/8; Fox, 1.5/5; ABC, 1.4/4; Univision, 1.2/4; NBC, 1.0/3; Telemundo, 0.7/2; CW, 0.6/2.

In total viewers: CBS, 9.9 million; ABC, 5.7 million; Fox, 5.3 million; Univision, 2.9 million; NBC, 2.5 million; Telemundo, 2.0 million; CW, 1.6 million.