When David Corvo, executive producer of NBC's "Dateline," heard rumblings at the beginning of the year that "The Jay Leno Show" was on shaky ground, he knew he had to prepare.

"I wasn't born yesterday, so I'm always thinking, 'Be ready, be ready,' " Mr. Corvo said. "We're the guys who come off the bench."

As NBC tries to patch together a new lineup for the 10 p.m. hour, it has called on "Dateline" to fill in the gap on Fridays by stretching the program to two hours, from 9 to 11 p.m., an expanded format that was originally slated to begin in May. That means the newsmagazine has 12 extra hours this spring.

When it returned to the air Friday after an Olympics-imposed hiatus, "Dateline" was up against a familiar foe: the ABC newsmagazine "20/20," which has also temporarily been expanded to two hours for several nights this spring.

The matchup will accentuate the fierce jostling between the newsmagazines for the biggest scoops. "20/20" came out of the gate Friday with exclusive home video of kidnap victim Jaycee Dugard, the first images of her since she was rescued last summer. The network paid a sum in the low six figures to license the footage from her family, according to a person familiar with the negotiations, a tactic regularly used by the television networks to secure competitive material.

"Dateline" weighed in with a dramatic two-hour show about a woman's efforts to free her husband from vicious kidnappers in Mexico.

It was the first time the programs faced off directly since last summer, when "Dateline" attracted an average audience of 6.2 million viewers, 28 percent more than "20/20's" 4.8 million, according to Nielsen.

"Competition really ups everyone's game," said David Sloan, executive producer of "20/20." "It's good for the viewers and it's good for the shows."

Both programs have largely moved away from the multistory format that originally defined network newsmagazines in favor of one long-form story per episode, an approach also embraced by CBS's "48 Hours Mystery," which has found success with its emphasis on crime mysteries.

"We just got into the theory of, 'Let's go deep,' " Mr. Corvo said. "I think in the current era of trying to hold people's attention, a story driven by narrative with suspense and conflict is successful."

TV columnist Rob Owen's Tuned In+ is featured exclusively on PG+, a members-only web site from the Pittsburgh Post-Gazette. Our introduction to PG+ gives you all the details.