NEW YORK - NBC worked feverishly to spread the word about Bob Costas' exclusive interview with former assistant Penn State football coach Jerry Sandusky, who is accused of sexually assaulting boys, even as the two men were still on the phone together.

Their talk, broadcast Monday on the "Rock Center" newsmagazine, was part of a remarkable evening of news interviews on broadcast TV. It competed directly with Diane Sawyer's interview with U.S. Rep. Gabrielle Giffords on ABC, which was ABC's most-watched news show since the summer.

The riveting interview with Sandusky, who is accused of sexually abusing eight boys over a 15-year period, was a surprise even to Costas. The veteran NBC Sports anchor was in a Manhattan studio for an interview with Sandusky's lawyer, Joseph Amendola, when the lawyer said, "What if I can get Sandusky on the phone?" Costas said Tuesday on MSNBC's "Morning Joe."

"I'm thinking, `I wonder from your standpoint whether that's the smartest thing to do,' but at the same time, sure if you want to do it. Let's get him on the phone," said Costas, who declined an interview request with The Associated Press through a spokeswoman.

About 10 or 15 minutes later, the interview began.

NBC immediately faced a challenge in how to publicize an interview with three hours' notice, particularly given that few people watch NBC's prime-time lineup. The interview was taped starting about 6 p.m. ET, and while it was still happening, a producer called to a nearby studio where Brian Williams was anchoring "Nightly News" to make sure Williams promoted it before he got off the air, said Rome Hartman, "Rock Center" executive producer.

"Rock Center" staffers also began tweeting quotes from the interview almost as soon as they left Sandusky's mouth, and the show's blog was updated. A video clip of the interview was posted online by about 7:30 p.m., with all TV networks given permission to use it.

Ultimately, "Rock Center" was seen by 3.87 million viewers, Nielsen said, well behind the 13.4 million people who watched the well-promoted interview with Giffords. That still beat the 3.46 million people who watched "Rock Center" the previous Monday, and clips of the interview were widely disseminated and discussed on Tuesday.

With countless journalists looking to speak to Sandusky, it's not clear why Costas was chosen. Perhaps his work in sports made him a more familiar and comfortable choice for a man who was Joe Paterno's top defensive assistant for many years at Penn State.

As television, the interview was minimalist: Phone interviews are rarely seen on TV because of the lack of video. NBC ran some still pictures of Sandusky, but otherwise the camera focused largely on Costas' face.

Costas was blunt, often uncomfortably so.

"What about Mike McQueary, the grad assistant who in 2002 walked into the shower where he says in specific detail that you were forcibly raping a boy who appeared to be 10 or 11 years old?" Costas asked. "That his hands were up against the shower wall and he heard rhythmic slap, slap, slapping sounds and he described it as rape?"

Sandusky answered that it was false.

Costas also asked specifically about touching boys' genitals and performing oral sex.

"There's no way to sanitize it," Hartman said. "If you do, you do a disservice to the viewers."

Perhaps the most arresting moment came when Costas asked Sandusky if he was sexually attracted to underage boys. Sandusky at first repeated the question, then said: "I enjoy young people. I love to be around them," before denying sexual attraction.

"I'll let the viewer infer what they want from that, but it was somewhat odd," Costas said on "Morning Joe."

Dona Hayes, chairwoman of Syracuse University's broadcast and digital journalism program, said she thought Costas did an outstanding job with the interview.

"He was respectful of the ongoing legal process, but at the same time he asked the pointed questions that echoed what many fair-minded people, in Costas' words, were thinking and asking," Hayes said.

Costas didn't sensationalize, attack or dismiss Sandusky, wrote Jeff Labrecque of Entertainment Weekly on Tuesday. "He stuck to the facts, and let Sandusky's words -- and silences -- do his work for him," he said.

It could be a defining moment for the Williams-hosted "Rock Center," in only its third episode and struggling in the ratings.

"This helped put us on the map," Hartman said. "It's not as if we were flying under the radar, but you need to give people a reason to watch if you're a new program."