A repeat of CBS comedy ”The Big Bang Theory” was easily the top-rated program among the major networks on a sluggish Thursday that saw ABC’s ”Duets” dip from its soft premiere of last week and Fox’s ”Touch” wrap its season in lackluster fashion. Also, CW’s ballet series ”Breaking Pointe” didn’t do much in its bow.

TNT was expected to win Thursday with its NBA conference finals playoff game between the Oklahoma City Thunder and San Antonio Spurs.

According to preliminary national estimates from Nielsen, CBS led the broadcast networks in demos as well as total viewers , even with an all-repeat lineup. ”The Big Bang Theory” (2.3 rating/8 share in adults 18-49, 8.7 million viewers overall) easily led its 8 o’clock half-hour and was the night’s top-rated broadcast program in all key adult categories, and ”Rules of Engagement” kept the net on top in 18-49 at 8:30 (1.8/6, 6.5 million viewers overall). From 9 to 11 p.m., the net was competitive across the board with encores of ”Person of Interest” (1.4/4 in 18-49, 7.4 million viewers overall) and ”The Mentalist” (1.3/4 in 18-49, 7.2 million viewers overall).

At ABC, singing competition ”Duets” (1.5/5 in 18-49, 5.9 million viewers overall) was down a bit from its modest premiere-night scores of last week, but led the Big Four in 18-49 during the 9 o’clock hour. It was followed by cop drama ”Rookie Blue” (1.4/4 in 18-49, 5.9 million viewers overall), which matched last week’s season-premiere score and continues to be a decent summertime performer for the net.

Fox aired the season’s final two episodes of rookie Kiefer Sutherland drama ”Touch,” generating nearly identical scores at 8 (1.3/5 in 18-49, 4.6 million viewers overall) and 9 (1.3/4 in 18-49, 4.7 million viewers overall). The show will air on Fridays in the fall.

NBC aired repeats of ”The Office” at 8 (0.8/3 in 18-49, 2.4 million viewers overall) and 8:30 (0.8/3 in 18-49, 2.2 million viewers overall), followed by special repeats of America’s Got Talent” at 9 (1.1/3 in 18-49, 3.9 million viewers overall) and 10 (1.5/5 in 18-49, 4.9 million viewers overall. The second ”Talent” delivered the best score in the Thursday 10 p.m. hour for NBC since the third episode of ”Awake” in mid-March.

At CW, ”Breaking Pointe” averaged a 0.3/1 in 18-49 and about 1 million viewers overall in the 8 o’clock hour, followed by an encore of the previous night’s premiere of hotel-based reality show ”The Catalina” (0.2/1 in 18-49, 0.5 million viewers overall).

Preliminary 18-49 averages for the night: CBS, 1.6/5; ABC, 1.5/5; Fox, 1.3/4; NBC and Univision, 1.2/4; CW, 0.3/1.

In total viewers: CBS, 7.4 million; ABC, 5.9 million; Fox, 4.7 million; NBC, 3.7 million; Univision, 2.8 million; CW, 0.7 million.