Fast National ratings for Sunday, March 21, 2010.
 
An NCAA Tournament overtime thriller carried nearly an hour into primetime and gave CBS a big bump and an easy victory on Sunday night.
 
Of course, all numbers are subject to change.
 
Among adults 18-49, CBS averaged a 3.7 rating, far ahead of the 2.1 rating for both FOX and ABC. NBC's 1.9 rating was a close fourth in the key demographic.
 
Overall, CBS averaged an estimated 13.19 million viewers to go with an 8.0 rating/13 share. ABC was a distant second with a 4.6/7, beating the 3.4/6 for NBC. FOX's 2.7/4 trailed.
 
CBS started the night in first with an 8.5/15 for what was 50 minutes of NCAA tournament coverage and the start of "60 Minutes" in most of the country. ABC's "Thin Ice" was second with a 2.9/5. NBC's "Dateline" was third, beating the 1.9/3 for two episodes of "'Til Death" on FOX.
 
In the 8 p.m. hour, CBS got a 7.9/13 from "60 Minutes" and "The Amazing Race." ABC's "Extreme Makeover: Home Edition" was second. FOX's "The Simpsons" and "The Cleveland Show" averaged a 3.1/5 overall and finished second in the key demo. NBC's "Minute to Win It" was fourth with a 2.9/5. 
 
CBS stayed in first at 9 p.m. with "The Amazing Race" and the start of "Undercover Boss," which had a 7.3/11. ABC's "Desperate Housewives" was a close second with a 6.8/10.NBC's "Celebrity Apprentice" was third. FOX's "Family Guy" (3.9/6) and "Sons of Tucson" (2.4/4) were fourth.
 
"Undercover Boss" and the start of "Cold Case" gave CBS an 8.2/14 in the 10 p.m. hour. NBC's "Celebrity Apprentice" improved to a 4.6/8. ABC's "Jamie Oliver's Food Revolution" was third with a 4.1/7 in its series premiere.
 
 
All ratings information comes from preliminary Fast National Nielsen data, which includes live and same-day DVR viewing. All numbers are subject to change, particularly in the case of live events.