HOLLYWOOD — Fox joined Ruben Studdard as a big winner during the last full week of May, as “American Idol” hit some of the net’s highest ratings notes ever.

For the week of May 19-25, according to Nielsen, Fox prevailed in all key demo categories including adults 18-49, where its 5.7 rating/17 share topped second-place NBC (3.4/10) by a whopping 68%. Net won five nights, led by the two-hour conclusion of “Idol,” which crowned Studdard its champ and set all-time Wednesday records for the network (14.9/36 in 18-49, 34.2 million viewers overall).

Fox also led the frame in total viewers (13.2 million) — just the fifth time in history that it has won a week by this measure without the help of major sporting events.

The week included the final three nights of the May sweep, which saw Fox edge out NBC in adults 18-49 (4.7 to 4.4) and CBS lead in overall audience (12.9 million).

The Wednesday seg of “American Idol” finished the season as the No. 3 program in both adults 18-49 (10.3/25, behind “Joe Millionaire” and “Friends”) and total viewers (21.93 million, behind “CSI” and “Joe Millionaire”).

Fox also received a strong perf from Tuesday drama “24,” whose season finale set a series high in total viewers (14.2 million).

Standout performer for NBC, second for the week in key demos, was Monday made-for “Martha, Inc.: The Story of Martha Stewart,” whose 18-49 rating (5.2/12) was the best for a single-part movie on any net since March 2002.

CBS, third in both 18-49 and 25-54, had a big Monday with the expanded season finales of “Everybody Loves Raymond” and “CSI: Miami,” which tied as the week’s top scripted program in 18-49 (7.4/18).

ABC was fourth in 18-49 and third in 18-34, led by the season finales of “NYPD Blue” (5.0/13 in 18-49), “Extreme Makeover” (4.8/12 in A18-49) and “My Wife and Kids” (4.0/10).

The WB finished fourth in both persons 12-34 and women 18-34, led by the finales of its top two shows: “Smallville” (5.1/13 in A18-34) and “7th Heaven” (3.7/11).

UPN remained sixth but delivered its best weekly average in adults 18-34 (1.7/5) since January, bolstered by the series finale of “Buffy the Vampire Slayer” and a credible start for reality skein “America’s Next Top Model.”

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NBC’s sweep stunt of Jay Leno and Katie Couric switching duties for a day generated strong ratings.

Final ratings for May 12 show that “The Tonight Show With Jay Leno,” featuring “Today’s” Couric as a special host, achieved a 3.4 rating among adults 18-49 and 8.9 million viewers overall — the best scores for the latenight skein since May 2, 2002. It was also the best result for “Tonight” on a Monday in seven years.

Leno’s guest-hosting duties on “Today” generated a 2.8 rating among adults 25-54 and 6.6 million viewers overall, helping the NBC show open up a commanding 44% winning margin over ABC’s “Good Morning America” that day.

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Annika Sorenstam’s historic day at the Colonial golf tournament produced record ratings for the opening round of a regular PGA tour event on the USA Network.

According to Nielsen, May 22 coverage of the first woman to play in a men’s professional event in 58 years produced a 1.6 rating in the roughly 87 million U.S. homes with cable television, meaning that about 1.5 million viewers were watching.

The previous record for the first round of a regular PGA Tour event on USA was a 1.58 rating at the Pebble Beach Pro-Am.