NEW YORK — The NFL draft has become such a popular television event that the first round on ESPN seemed to steal viewers from some of the biggest networks' Thursday shows.

An estimated 7.3 million watched the draft Thursday, its ratings up 23 percent from 2009, the Nielsen Co. said. ESPN's three days of draft coverage, two of them in prime time, drew the biggest audience this event has ever received.

Meanwhile, CBS' "CSI: Crime Scene Investigation" had the third-smallest audience in the show's history. NBC's "Community" and "Marriage Ref" had series lows, and "The Office" had its smallest audience since moving to Thursdays in 2006, Nielsen said.

The first night of "America: The Story of Us" on History on Sunday grabbed 5.7 million viewers, Nielsen said. That's second only to an episode of "Pawn Stars" for the most-watched show in the cable network's history.

Once a proven performer, the "Hallmark Hall of Fame" movie on CBS was a disappointment Sunday. The movie "Love is Not Enough" barely had 7 million viewers.

The premiere of ABC's "Romantically Challenged" comedy had a stronge audience for its premiere, ranking No. 15 in the ratings with 10.7 million viewers.

Despite some sagging numbers for "American Idol," the emergence of "Glee" as a strong performer helped Fox win the week with an average prime-time viewership of 9.2 million (5.4 rating, 9 share). CBS had 8.4 million (5.3, 9), ABC had 7.4 million (4.7, 8), NBC had 5.7 million (3.7, 6), the CW had 1.7 million (1.1, 2) and ION Television had 920,000 (0.6, 1).

Among the Spanish-language networks, Univision led with an average of 3.3 million viewers in prime time (1.7 rating, 3 share). Telemundo had 1.1 million (0.6, 1), TeleFutura had 850,000 (0.4, 1), Estrella had 300,000 and Azteca 220,000 (both 0.1, 0).

NBC's "Nightly News" topped the evening newscasts with an average of 7.6 million viewers (5.1, 11). ABC's "World News" was second with 7.1 million (4.8, 10), and the "CBS Evening News" had 5.1 million viewers (3.5, 7).

A ratings point represents 1,149,000 households, or 1 percent of the nation's estimated 114.9 million TV homes. The share is the percentage of in-use televisions tuned to a given show.

For the week of April 19-25, the top 10 shows, their networks and viewerships: "Dancing With the Stars," ABC, 21.07 million; "American Idol" (Tuesday), Fox, 19.67 million; "American Idol" (Wednesday), Fox, 18.82 million; "The Mentalist," CBS, 14.96 million; "Dancing With the Stars Results," ABC, 13.56 million; "CSI: Crime Scene Investigation," CBS, 13.35 million; "Glee," Fox, 12.98 million; "Survivor: Heroes & Villains," CBS, 11.89 million; "The Big Bang Theory," CBS, 11.66 million; "CSI: Miami," CBS, 11.66 million.