“I threw your name into the hat. You’re going to get a call.”

So said Mike Fucci, a senior Deloitte executive, to Barbara Adachi. Fucci had heard about a big job opening—running the western region of Deloitte’s human capital advisory services—and pitched Adachi as the right person for the post. While the idea of stepping up to manage 120 people spread across multiple offices gave Adachi butterflies, she was game for the challenge.

Adachi got the promotion and turned in the strongest financial results the region had ever seen. The job catapulted the San Francisco mom of one to even bigger things. Late last year, Adachi, 60, was named national managing director for human capital of the New York City–based professional services firm.

Was Fucci just a terrific guy? Yes, and no—officially, he serves as Adachi’s sponsor. Sponsorship, where a senior leader uses political clout to advocate for an employee’s advancement, can do big things for talent like Adachi. in fact, it may be the missing link in moving more women into top executive roles. A recent report by the Center for Work-Life Policy (CWLP) notes that “the pipeline is fairly bursting with proven female talent.” And yet, according to the New York City think tank, “women who are qualified to lead stall out in their careers not for lack of drive, but rather for lack of push. They simply don’t have the powerful backing necessary to propel them through the straits of upper management.”

Women represent more than half of entry-level workers (53 percent), but these numbers dwindle as we step up the ladder. only 34 percent of senior management, 16 percent of corporate officers and 3 percent of Fortune 500 ceos are women, according to the CWLP. This remains the case despite studies showing that companies run by diversified executive teams—including women— outperform those without diversity.

It’s fitting, then, that Working Mother unveils its first Best Companies for Women’s Advancement. These ten organizations outdo their Working Mother 100 Best Companies peers in putting mentoring, leadership training and manager training and accountability to work to help women fulfill their potential. And, perhaps critically, in recent years, they’ve all added sponsorship programs to the mix. “Sponsorship can expand a woman’s number of opportunities and the scale of those opportunities,” explains Nancy Dunn, manager of diversity and inclusiveness for Fairfield, CT–based General Electric, one of this year’s Best Companies for Women’s Advancement.

American Express, another winner, believes sponsorship is key to retaining highly valued mid- and senior-level leaders. Since 2008, the financial giant has reviewed cases of female senior leaders leaving the company. “we saw that the senior woman experienced a change in sponsor relationship prior to her departure—he left the company, they had a falling-out, or she moved to a part of the company where this sponsorship had no effect,” says Kerrie Peraino, 43, the financial firm’s chief diversity officer and mom to Samantha, 12, Harrison, 10, and Elizabeth, 2.

Sponsors vs. Mentors
If sponsorship is so powerful, why isn’t it more common? While all of our Best Companies for Women’s Advancement offer it, only 38 percent of the much larger group of Working Mother 100 Best Companies do.

Sponsorship often gets confused with mentoring, but the two roles are different. Mentors provide advice, and such relationships can be formed among peers, bosses and junior staff. By contrast, sponsors are senior executives with the clout to advance their protégés. “A sponsor pounds the table for you to get the raise, the promotion or the chance to work on a high-profile project,” says Susan Bulkeley Butler, author of Women Count: A Guide to Changing the World.

While men embrace sponsorship, some women shy away from the notion that they need a “favor” or special treatment to get a promotion. “What research has shown is that excellent skills will get you far—but only so far,” notes Arin Reeves, president of nextions, a Chicago-based consultancy specializing in leadership and inclusion training for Fortune 500 companies. She says women over-rely on mentors (where the goal isn’t necessarily advancement) and underestimate the importance of getting the backing of a sponsor.

Finding the “Click”
For the sponsor-protégé relationship to thrive, “there needs to be personal chemistry and mutual trust,” says Susan Lyon, 43, global HR director for Procter & Gamble’s Duracell brand. Several years ago, when Lyon was considering her next career move, her sponsor at the Cincinnati-based consumer products leader advised her to reach for an international role as a country human resource manager.

When a highly coveted spot opened for Australia and New Zealand, Lyon’s sponsor not only lobbied for her, he rallied several other influencers to put in calls to the executive in charge of filling the position. Lyon, a mom of two, landed the role and calls the years her family lived in Australia “life changing.” Her work abroad enabled her to take a bigger role when she returned.

To gain the greatest support, your sponsor should ideally be a level or two above your boss, says Nancy Calderon, national partner of U.S. operations and chief administrative officer for the Americas at KPMG, the global professional services firm. To defuse any potential awkward politics, she adds, you should tell your boss what you are seeking in a sponsor and ask if she is willing to introduce you to a potential candidate.

A Vision of Success
A great sponsor will challenge a protégé. Jessica Igoe, VP of global sponsorship and event marketing at American Express, recalls when her twins were a year old and she spotted a posting for a dream job that also required a lot of travel. Igoe, 36, met with her sponsor, Lisa gregg, and the senior exec hiring for the post. Gregg helped strike a deal allowing igoe to work two days a week from home to balance her travel. igoe worked on prestigious corporate sponsorship projects such as Wimbledon and was promoted to VP. It’s a hotshot path she’s thrilled to be on.

“Your sponsor gives you the push you need,” she says. “that person has a vision for your success even before you do.”