With Michael Phelps out of the pool, NBC’s Olympic ratings not surprisingly slipped last night compared to the prior week. That may have given CBS’s 8 p.m. comedies a boost.

The combination of “The Big Bang Theory” and “How I Met Your Mother” averaged a 2.0 adults 18-49 rating, according to Nielsen overnights, up 18 percent over a combined 1.7 last week.

It came on a night where NBC saw big declines from the previous week, with its primetime average falling 19 percent, from a 10.2 to an 8.3. Of course, that was no surprise. Everyone expected the Games to fall back once Phelps, who won a record eight golds, finally climbed out of the pool.

Still, the Games dip may not have been the only thing helping CBS’s first hour. The network also may have benefited from a week-to-week slide by ABC’s reality bomb “High School Musical: Get in the Picture,” which slipped from a 0.8 last week to a series-low 0.5 last night at 8 p.m.

CBS’s 9 p.m. and 10 p.m. hours were about on par with the previous week.

Meanwhile, NBC was first for the night among 18-49s with an 8.3 average overnight rating and a 23 share. CBS was second at 2.0/5, Univision third at 1.6/4, Fox fourth at 0.9/2, ABC fifth at 0.8/2 and CW sixth at 0.5/1.
 
Ratings for NBC are approximate as fast nationals measure 8 to 11 p.m. timeslot data and not actual program data. The Olympics lasted well past 11 p.m.
 
At 8 p.m. NBC led with a 6.6 for Olympics, followed by CBS with a 2.0 for repeats of “Theory” and “Mother.” Univision was third with a 1.8 for “Al Diablo con los Guapos,” Fox fourth with a 1.0 for a repeat of “Prison Break,” CW fifth with a 0.6 for a “Gossip Girl” rerun and ABC sixth with a 0.5 for “High School Musical: Get in the Picture.”
 
NBC was first again at 9 p.m. with an 8.7 for more Olympics, while CBS held onto second with a 2.2 for repeats of “Two and a Half Men” and “The New Adventures of Old Christine.” Univision remained third with a 1.8 for “Fuego en la Sangre,” with ABC fourth with a 0.9 for the first hour of the movie “Bewitched,” Fox fifth with a 0.8 for a repeat of “Terminator: The Sarah Connor Chronicles” and CW sixth with a 0.5 for a “One Tree Hill” rerun.
 
At 10 p.m. NBC extended its lead with a 9.6 for the Olympics, with CBS second with a 1.7 for a repeat of “CSI: Miami.” Univision was third with a 1.1 for “Cristina” and ABC fourth with a 1.0 for the second half of “Bewitched.”
 
NBC also led the night among households with a 15.3 average overnight rating and a 25 share. CBS was second at 4.2/7, ABC and Univision tied for third at 2.0/3, Fox fifth at 1.8/3 and CW sixth at 0.8/1.