Talk about the miracle bra.

When Brandi Chastain scored the winning shot in a tense, overtime shootout with China in the World Cup soccer final, she did more than just shed her shirt to celebrate the team's triumph. She fired the hopes of sports-bra makers everywhere, who now are betting that fans who supported the team will rush out to buy the undergarments that supported the players.

Nike Inc., the company that manufactured that now-famous bra and pays Chastain to wear its products, has pushed up the launch date of its first line of sports bras in hopes that the publicity windfall will translate into millions.

Retailers, meanwhile, have been rushing to capitalize. On Tuesday, Roadrunner Sports of San Diego fired off e-mails to customers and posted ads on its Web site to trumpet a three-day, 20-percent-off promotion for its collection of sports bras.

"It's gone crazy. We've seen some remarkable increases," said Roadrunner spokeswoman Carol Jansen D'Agnese, who added that sales of sports bras are up 25 percent this week alone.

Nike competitors, such as Fila and Reebok, are calculating that Chastain's act will benefit all players in this $230 million-a-year market. There is little doubt that her singular product unveiling could scarcely have been better-timed. With the back-to-school season approaching, sports marketing experts expect sports bras to become must-have accessories for tens of thousands of teenage girls, even those who are not athletically inclined.

"I wouldn't be surprised to see exponential-type growth," said Michael Mays of the Sporting Goods Manufacturing Association.

In the era of Victoria's Secret, sports bras seem downright dowdy -- scarcely racy enough to cause a stir. Reebok has been trying to position the bra as outerwear. For months, tennis star Venus Williams has been wearing Reebok sports bras without any shirt, without raising many eyebrows.

"It's already becoming more a fashion-style piece of clothing," said Todd Dalhausser, manager of sales planning at Reebok.

Still, Chastain's victory strip got a huge rise out of fans and gave yet another Nike product the sheen of controversy that the company so regularly and carefully applies to new products. Plenty of onlookers were taken aback by the disappearance of Chastain's shirt. Others have decried it as a setback for women's sports. "It was a huge plus for Nike and Brandi," said Bob Williams of Burns Sports, a Chicago marketing firm. "But as far as trying to attract fans to women's sports and for breaking down stereoptyes, I think it was a minus."

Then there is the lingering question of whether Chastain had scripted this seemingly unscripted episode as a publicity stunt to add value to her endorsement deal with Nike. Her agent has denied it, but there is little doubt that Chastain's gambit was years in the making. Nike has been plotting its foray into the sports-bra market with a focus and intensity reminiscent of the Manhattan Project and the 30-year-old Chastain was part of the team that helped design the final product.

Last April, the company invited Chastain and about 20 other female athletes to its headquarters in Oregon for a one-day sports-bra summit. Participants criticized the offerings now on the market as too bulky and uncomfortable and offered some ideas about how to cure these problems.

For all that planning, some experts said yesterday that Nike might have enjoyed an even bigger financial bounce had Chastain kept her shirt on. The bra she wore is emblazoned with a relatively inconspicuous swoosh just above the left breast, in hard-to-see gray on black. The shirt she was wearing, like the shirts of all the U.S. players, sported a company logo that was far easier to spot.

"Had that swoosh been more visible that would cause the public to say, `I want that kind,' " said Mike Mays of the Sporting Goods Manufacturers Association. "But because it was a plain design and didn't have any noticeable corporate affiliation, I think it will end up benefiting everybody."

CAPTION: Brandi Chastain holds up the Sports Illustrated cover photo of her reaction after scoring the point that won soccer's Women's World Cup for the U.S. team.