PITTSBURG, Calif. — As a "greeter," the cheerful Betty Dukes is one of the first employees customers usually see as they walk through the front doors of the Walmart store here.

As the first "named plaintiff" in Dukes v. Wal-Mart Stores Inc., the ordained Baptist minister also is the face of the largest gender bias class-action lawsuit in U.S. history — one that could cost the world's largest private employer billions.

Her dual roles have turned her into a civil rights crusader for the company's many critics, who have dubbed the legal battle "Betty v. Goliath." It is a far cry from where Dukes expected to be when she enthusiastically accepted an offer in 1994 to work the cash registers part-time for $5 an hour. She dreamed of turning around a hard life by advancing, through work and determination, into Walmart corporate management.

"I was focused on Walmart's aggressive customer service," Dukes said in an interview during her lunch break, after first saying grace over a meal of fast-food hamburgers and chicken nuggets. "I wanted to advance. I wanted to make that money."

But by 1999, her plans were in tatters. Several years of little advancement and frustration with her role culminated with an ugly spat with managers that resulted in a humiliating demotion and a pay cut, she said.

That also became the genesis of the federal class-action lawsuit U.S. District Judge Martin Jenkins called "historic" while he was handling the case. Last Monday, the 9th U.S. Circuit Court of Appeals upheld Jenkins' decision allowing the case to go to trial as a class action on behalf of as many as 1 million former and current female Walmart employees.

Jenkins has since stepped down from the federal bench and the case will now be handled by U.S. District Judge Vaughn Walker, who is also deciding another high profile case: the legality of California's voter-approved ban on same-sex marriages.

Dukes' lawsuit alleges Walmart is violating the 1964 Civil Rights Act, which made it illegal for employers to discriminate on the basis of race, creed or gender. Dukes alleges that Walmart systemically pays women less than their male counterparts and promotes men to higher positions at faster rates than women.

The Bentonville, Ark.-bas- ed retailer denies the accusations and argues that if there are any instances of discrimination they are isolated and not an overarching company policy. Walmart says any such cases should be handled as individual lawsuits, not as a class action.

The retailer has fiercely fought the lawsuit since it was first filed in federal court in San Francisco in 2001 and said it would appeal the most recent decision to the U.S. Supreme Court.

PIVOTAL MOMENT

The incident that sparked the epic legal battle began while Dukes served as a customer service manager.

Dukes, 60, needed change to make a small purchase during her break. She asked a colleague to open a cash register with a one-cent transaction, which she claims was a common practice.

Nevertheless, she was demoted for misconduct. She complained to a manager that the punishment was too severe and part of a long campaign of discrimination that began almost as soon as she started working for Walmart in this blue-collar city of about 100,000, some 45 miles east of San Francisco.

She believed the reprimand was partially motivated by race. She's black and the managers were white.

When those complaints were ignored, Dukes sought legal advice.

She ended up being represented by Brad Seligman, an attorney who had launched The Impact Fund, a legal nonprofit, in 1992.

Seligman said he asked Dukes to serve as lead plaintiff in what would become a vast class action because of her strong personality.

"I'm somewhat in awe of her, particularly that she has managed to work at Walmart for all these years," Seligman said. "It is extraordinarily difficult to find someone who wants to risk their job by filing a lawsuit against their employer."

Seligman and other attorneys told Dukes that she wasn't alone, that many other women had similar complaints. They said they would like to use her and five other former and current Walmart employees to file the class-action lawsuit.

"My jaw fell open," Dukes said when told of the other complaining women. "I thought I was by myself."

That was nine years ago. And with Walmart insisting the lawsuit is without merit and vowing to continue its fight, it appears the litigation has more years to go.

Dukes is undeterred by that prospect and sanguine about the outcome.

"It's a very courageous thing for a person to do, to stick with it over such a long period of time," said Marcia Greenberger, founder of the Washington, D.C., advocacy group National Women's Law Center. "The individuals who step forward pay a very big price to be willing to tell their stories and to hold their records up to public scrutiny."

The center has filed a "friend of the court" brief supporting the Dukes lawsuit, as have the NAACP and Mexican American Legal Defense & Educational Fund. The U.S. Equal Employment Opportunity Commission has also filed a brief supporting the lawsuit.

The U.S. Chamber of Commerce and other organizations, fearful that a ruling in Dukes' favor will expose other companies to costly lawsuits, have filed briefs urging dismissal of the complaint.

Ms. Magazine named her one of its "Women of the Year" for 2004, the same year Liz Featherstone's book "Selling Women Short: The Landmark Battle for Workers' Rights at Wal-Mart" was published. Featherstone has compared Dukes to civil rights crusader Rosa Parks.

"I am very grateful that I'm on this platform," Dukes said. "In this life, you have to stand up or be trampled."

Dukes said that there have been few problems with managers and co-workers since the lawsuit was filed in 2001. She said the work atmosphere gets a "little chilly" after courtroom victories are reported in the media.

And Seligman, her lawyer, said her involvement in the lawsuit may even have benefited her.

"It seems that at every pivotal moment in the litigation," Seligman said, "Betty gets a raise."