It's a rare -- if not unprecedented -- occurrence when two television shows tie for first place in the Nielsen ratings. But in fact that's what occurred last week -- and the two shows had the same name, America's Got Talent . Both the Tuesday and Wednesday episodes of the NBC summer series captured a 6.2 rating and an 11 share, but Wednesday's had a few more viewers, 10.67 million versus Tuesday's 10.48 million. The remaining shows on the top-ten list aired on CBS, except for ABC's Wipeout , which tied for ninth place. Among the nightly newscasts, NBC Nightly News with Brian Williams put some space between itself and ABC World News with Diane Sawyer after weeks in which the ABC newscast narrowed the gap and appeared poised to take over the lead. However, last week the NBC newscast grabbed 7.54 million viewers, versus 6.81 million for ABC. CBS Evening News with Katie Couric remained a distant third with 5.26 million viewers. For the week, CBS led the field in total viewers with a 4.1 rating and a 7 share. NBC placed second with a 3.1/6. Fox placed third with a 2.9/5, while ABC trailed with a 2.7/5.

The top ten shows of the week according to Nielsen Research 1. America's Got Talent (Wednesday), NBC, 6.2/11; 1. (Tie) America's Got Talent (Tuesday), NBC, 6.2/11; 3. NCIS, CBS, 5.8/10; 4. Two and a Half Men , CBS, 5.5/9; 5. 60 Minutes, CBS, 5.4/9; 6. The Big Bang Theory, CBS, 5.3/9; 7. NCIS Los Angeles, CBS, 4.9/8; 8. The Mentalist , CBS, 4.6/8; 9. Wipeout (Tuesday), ABC, 4.4/8; 9. (Tie) Big Brother (Sunday), CBS, 4.4/7.