The U.S. women’s national team won last year’s World Cup title, drawing the largest American TV audience ever for a soccer game. (Elaine Thompson/AP)

Five members of the U.S. women’s national soccer team, whose international accomplishments and domestic appeal have dwarfed those of its male counterpart for years, filed a complaint with the Equal Employment Opportunity Commission on Thursday alleging wage discrimination against the sport’s governing body in the United States.

Carli Lloyd, Becky Sauerbrunn, Alex Morgan, Hope Solo and Megan Rapinoe filed the action on behalf of their entire team, which captivated the country during its run to the 2015 Women’s World Cup title. The players argued their financial impact and on-field success demands equal pay compared to the men’s national team, continuing a years-long battle against the U.S. Soccer Federation.

The wage gap between genders has been a persistent issue in the American workplace for decades, including among athletes. What makes this case different is that the income disparity flies in the face of the women’s financial success — in recent years, their team has brought in significantly more revenue than the men’s team.

According to the complaint, members of the women’s national soccer team can expect to make roughly half of what their male counterparts earn despite playing more often, winning more games and drawing larger television audiences. U.S. women’s national team members earn between 38 percent and 72 percent of what men earn for each international exhibition match. The pay scale trickles down to small details, including female players receiving $50 per diem for food for domestic games and men’s players pocketing $62.50.

From left, World Cup-winning U.S. soccer players Carli Lloyd, Alex Morgan, Megan Rapinoe, Becky Sauerbrunn and Hope Solo filed a wage discrimintion claim on behalf of their entire team. (Associated Press)

For the financial year of April 2015 through March 2016, the USSF projected to lose $429,929, according to its most recent annual report. But owing “almost exclusively” to the success of the women’s national team and a victory tour following the World Cup, the complaint read, the USSF expects to profit $17.7 million. For the 2017 fiscal year, the USSF projects to profit $5 million from the women’s national team and lose $1 million off the men’s team.

The USSF responded to the claim later Thursday, saying it was “disappointed” but committed to resolve the dispute through collective bargaining.

The U.S. women’s 5-2 victory over Japan in the World Cup final last July averaged 25.4 million television viewers, making it the most-watched soccer game in U.S. history. In 2014, the U.S. men averaged 18.2 million and 16.5 million viewers in their two most-watched World Cup games.

The USSF still devotes far more resources to the men’s team. According to the federation’s 2015 financial report, it spent $31.1 million on expenses for the men’s team compared to $10.3 million for the women.

“The numbers speak for themselves,” Solo said in a news release. “We are the best in the world, have three World Cup championships, four Olympic championships, and the USMNT get paid more to just show up than we get paid to win major championships.”

Jeffrey Kessler, the attorney representing the women’s players, said in a telephone interview with The Washington Post that the complaint is akin to asking a district attorney to investigate a crime. The EEOC, the federal agency that enforces civil rights laws against workplace discrimination, will now conduct an investigation into the matter and decide if there has been a violation.

“We’re hopeful that we’ll get the right result, or that U.S. Soccer will do the right thing and agree to equal compensation,” Kessler said, adding that there have been many precedents for such an investigation outside of the sports world.

What’s unusual about this case, Kessler said, is that both the men’s and women’s soccer teams work for the same employer.

“So it fits squarely into the Equal Pay Act,” Kessler said, referring to the 1963 federal law that seeks to end wage disparity between men and women.

The timing of the quarrel stems from an unresolved collective bargaining agreement the USSF and women’s national team have been sparring over for years. The last CBA between the sides expired in December 2012, and they have since operated under a memorandum of understanding, according to 2015 USSF financial statements. Whether that memo, which essentially extended the previous CBA, is legally valid through the end of this year is the subject of a lawsuit filed by U.S. Soccer in February against the players’ union for the women’s team.

“In early January, the Women’s National Team Players Association submitted a reasonable proposal for a new CBA that had equal pay for equal work as its guiding principle,” Kessler said in the release. “U.S. Soccer responded by suing the players in an effort to keep in place the discriminatory and unfair treatment they have endured for years.”

In a statement later Thursday, the federation called itself “a world leader in promoting the women’s game” and said it hoped to reach a new CBA with its women’s team.

“We are committed to and engaged in negotiating a new collective bargaining agreement that addresses compensation with the Women’s National Team Players Association, to take effect when the current CBA expires at the end of this year,” the USSF said in the statement. “U.S. Soccer will continue to be an advocate on the global soccer stage to influence and develop the women’s game and evolve FIFA’s compensation model.”

The fight is reflective of an outlook that permeates across sports. Every major tennis tournament has distributed equal purses to men and women since 2007, when Wimbledon became the last to make pay equal. Even in tennis, though, the notion of equal pay is met with resistance.

The soccer team’s complaint comes shortly after Raymond Moore, chief executive of a prominent annual professional tennis tournament in Indian Wells, Calif., was forced to resign after he claimed female tennis players “ride the coattails of men.” Moore added: “If I was a lady player, I’d go down every night on my knees and thank God that Roger Federer and Rafa Nadal were born, because they have carried this sport. They really have.”

While the public met Moore with scorn, top-ranked men’s star Novak Djokovic, of Serbia, responded to the controversy by applauding the Women’s Tennis Association but adding that male players “should fight for more because the stats are showing that we have much more spectators on the men’s tennis matches. I think that’s one of the reasons why maybe we should get awarded more. Women should fight for what they think they deserve and we should fight for what we think we deserve.”

Djokovic added he had “tremendous respect” for female athletes because “their bodies are much different to men’s bodies. They have to go through a lot of different things that we don’t have to go through. You know, the hormones and different stuff, we don’t need to go into details.”

Djokovic later backed down from his comments.

Beyond the purview of USSF, the women’s national soccer team faces an uphill climb. In many foreign countries, women’s soccer remains overlooked. FIFA, the sport’s global governing body, awarded the U.S. women $2 million for winning the World Cup in 2015, compared with the $35 million it gave the champion German men in 2014. The American men, in fact, earned $9 million for losing in the round of 16.

Women’s soccer must also confront dangerous playing surfaces. Last December, the U.S. team canceled an exhibition match at Honolulu Stadium after current and former players complained publicly about the conditions of the artificial turf. The match was canceled two days after Rapinoe suffered a major knee injury while practicing on similarly beat-up turf. Men’s national teams are almost never asked to play on any surface but grass.

For now, the U.S. women’s team has focused on equal pay from the same organization that pays male counterparts in its own country. Its viewpoint can be summed up in the penultimate paragraph of the players’ complaint: “There are no legitimate, non-discriminatory reasons for this gross disparity of wages, nor can it be explained away by any bona fide seniority, merit or incentive system or any other factor other than sex.”

Matt Bonesteel contributed to this report.