NEW YORK — NBC is enjoying a taste of what superstar swimmer Michael Phelps savored last week: a clean sweep.

But unlike Phelps in Beijing's Water Cube, NBC's prime-time Olympics coverage left all its competition far behind.

In the first full week of the Summer Games, TV's seven top-rated shows were NBC Olympics broadcasts, helping NBC score an average of 28.7 million viewers, while its nearest rival, CBS, averaged just 5.1 million, according to Nielsen Media Research figures released Tuesday.

That audience margin between the winner and runner-up networks was the widest recorded by Nielsen since its People Meters were introduced two decades ago, NBC said.

ABC averaged 3.5 million viewers, followed by Fox with 3.2, CW with 1.5 million, and My Network TV with 1 million.

Among the Spanish-language networks, Univision averaged 3.4 million viewers, Telemundo had 1.00 million, TeleFutura 560,000 and Azteca 190,000.

NBC's "Nightly News" had its own golden glow: It handily won the evening news ratings race, averaging 9.4 million viewers (6.5 household rating, 14 share). ABC's "World News" had 6.9 million viewers (4.8 rating, 10 share) and the "CBS Evening News" 5.6 million viewers (3.8 rating, 8 share).

A ratings point represents 1,128,000 households, or 1 percent of the nation's estimated 112.8 million TV homes. The share is the percentage of in-use televisions tuned to a given show.

For the week of Aug. 11-17, the top 10 shows, their networks and viewerships: 1. Summer Olympics-Tuesday, NBC, 34.01 million; 2. Summer Olympics-Saturday, NBC, 31.59 million; 3. Summer Olympics-Monday, NBC, 30.17 million; 4. Summer Olympics-Thursday, NBC, 29.71 million; 5. Summer Olympics-Wednesday, NBC, 27.66 million; 6. Summer Olympics-Sunday, NBC, 27.18 million; 7. Summer Olympics-Friday, NBC, 26.07 million; 8. "Two and a Half Men," CBS, 8.07 million; 9. "NCIS," CBS, 7.22 million; 10. "60 Minutes," CBS, 7.09 million.