In a race that wasn’t as tight as expected, NBC won the adults 18 to 49 February sweeps crown with a 4.8 Nielsen Media Research rating, six-tenths of a ratings point ahead of CBS and Fox, which tied for second.

CBS won total viewers with an average 13.9 million. UPN was the only network to show year-to-year gains, up 13 percent in adults 18 to 49 and up 9 percent in total viewers.

“NBC will win the February sweeps by a margin that will surprise even us,” Jeffrey Zucker, NBC president of entertainment, news and cable, said last week. NBC was flat year to year in adults 18 to 49 and down 4 percent in total viewers, averaging a second-place 12 million.

With Fox airing “American Idol” two or three times a week and CBS and ABC having young-adult magnets in the Grammy Awards and Academy Awards presentations, respectively, NBC owes a big thanks to Mark Burnett and Donald Trump, executive producers of the network’s newest hit “The Apprentice.”

“The Apprentice” stormed in and shored up NBC’s Thursday night, which had been having performance trouble with sitcoms not named “Friends.” “Apprentice” averaged a 9.6 rating in adults 18 to 49 during February sweeps, which is up 33 percent from the 9 p.m.-to-10 p.m. time period’s performance in November sweeps (7.2 rating).

CBS won the February sweeps in total viewers by nearly 2 million viewers over second-place NBC, its widest margin of victory in 11 years and its fifth sweeps victory in a row. The network also finished in its closest competitive position to first-place NBC in adults 18 to 49 since 1993. Sweeps to sweeps, CBS was flat in adults 18 to 49 and in total viewers.

“The reason for CBS’s momentum is simple,” said CBS Chairman and CEO Leslie Moonves. “We have the deepest and best roster of programming.”

In the past two years CBS has developed seven successful new dramas and comedies, all of which will return to the schedule next year, Mr. Moonves said.

UPN was boosted by the stellar performance of “America’s Next Top Model.” “Model” averaged a 3.4/8 in adults 18 to 49 during the February sweeps, up 325 percent from the 0.8/2 that comedies were averaging in the time period last year. It also averaged 7 million total viewers, up 263 percent from last year’s 1.9 million time slot average.

“The addition of `Top Model’ has made UPN more competitive on Tuesday night than ever before,” said UPN Entertainment President Dawn Ostroff.

UPN beat The WB for a fifth-place finish in adults 18 to 49 with a 1.7/4 to The WB’s 1.6/4. UPN and The WB tied in total viewers with 3.9 million. The news wasn’t good for The WB, which is down 20 percent in adults 18 to 49 and 12 percent in total viewers.

Fox’s “American Idol,” which pulls from The WB’s 12- to 34-year-old target audience, did a lot of damage to “Gilmore Girls,” “Smallville” and even “7th Heaven” when Fox spread “Idol” to Mondays several times during the sweeps.

Jordan Levin, co-CEO of The WB, said that while scripted programming is the backbone of the network, The WB was hurt because it didn’t have a big reality show that viewers flocked to.

“If we made a mistake, the mistake was either not recognizing or not wanting to recognize the acceptance that advertisers were going to have for reality programming,” he said. “I think we woke up in the fourth quarter to that.”

Mr. Levin said the network has stepped up its reality program development to rebalance the schedule in the coming months.

Fox finished the sweeps tied for second with CBS in adults 18 to 49 but down 26 percent from February sweeps last year. Fox Entertainment President Gail Berman called the network’s February performance solid, considering Fox did not have a hit of the magnitude of “Joe Millionaire” in the sweeps as it did last year.

At the end of the sweeps, Fox was No. 2 for the season in adults 18 to 49, only two-tenths of a rating point behind NBC. “We’re closer to No. 1 than we were a year ago,” Ms. Berman said.

Despite having a ratings powerhouse in “American Idol” on Tuesday and Wednesday nights, the network’s dismal Thursday and Friday night ratings canceled out any huge gains. During the sweeps Fox averaged a 7/20 in adults 18 to 49 on Tuesdays and a 6.3/16 on Wednesdays but only mustered a 2/5 on Thursdays and a 1.9/6 on Friday nights.

The lack of scripted shows on Fox’s air during the sweeps was notable-only 26 of Fox’s 60 hours programmed during February sweeps were filled with scripted programming, and five of those hours were movies. On 13 of the 28 nights of sweeps, Fox aired no scripted programming, although four of those nights were Saturday nights, where Fox has run its successful “Cops” and “America’s Most Wanted” franchises for many years. Fifty-seven percent of Fox’s sweeps schedule consisted of unscripted programming.

ABC finished the sweeps in fourth place in adults 18 to 49 with a 3.6/10 and third place in total viewers with 10.3 million. ABC Entertainment Television Group Chairman Lloyd Braun said the network’s core strength has been its comedy blocks, with nine of its sitcoms ranking first or second in their time period this season in the demo.

“Our big problem is that none of them are sledgehammers yet,” Mr. Braun said. “We just don’t slaughter the competition the way that NBC, CBS or Fox does.”

ABC’s comedies, however, have been hammered by “Idol,” which faces off against three ABC sitcoms. On Tuesdays, before “Idol” premiered, “8 Simple Rules” averaged a 5.1/15 in adults 18 to 49. (“Rules” did have unusually high ratings in its first three airings, the last episodes that featured the late John Ritter.) With “Idol” competition, the show is averaging a 2.8/7.

“I’m With Her” dropped from a 3.9/11 average pre-“Idol” to a 2.4/6 on Tuesdays, while Wednesday’s “It’s All Relative” dropped from a 3.7/10 to a 2.5/6. ABC’s 8 p.m. sitcom “My Wife and Kids” has also taken a hit because of numerous hour-long “Idols” on Wednesdays. It dropped from a 4.3/13 average before “Idol” to a 3.3/9.

The network did have some good news on the last night of sweeps-“Stephen King’s Kingdom Hospital” was the highest-rated new drama premiere on the network in 21/2 years. It won its two-hour time slot in adults 18 to 49 with a 5.5/14 and 14.1 million total viewers.