By most measures, Americans of varying political persuasions believe Hillary Clinton won the first debate. She displayed more policy gravitas and landed more attacks. But perhaps Clinton’s biggest win of the night was not in what she said, but in what she didn’t say. More specifically in what was, or rather was not, written on her face. Hillary’s face (or what from here on out may be known colloquially as “Hillary Face”) not only delivered her a much-needed first debate victory but may end up serving as a roadmap for women in the workplace everywhere.

In a debate that tackled such monumental life and death issues as racial profiling, police brutality, and nuclear arms, an analysis of how candidates look can seem… well, shallow. But we all know from history that candidate appearance can matter. For women the stakes are higher. Plenty of anecdotal evidence and studies confirm that female candidates and elected officials are judged on their looks in ways men are not. In addition to more “feminine” female candidates faring better with voters, Sen. Kirsten Gillibrand shared the fact that multiple male colleagues have commented on her fluctuating weight. And attractiveness.

As if fitting traditional standards of beauty and femininity weren’t enough, women also have to worry about our facial expressions more than men. Last year, science finally confirmed what any woman who has ever been catcalled while walking down a street has long known: Not wearing a naturally pleasant facial expression can cost us. RBF, short for Resting Bitch Face, is a phenomenon in which one’s neutral facial expression reads as irritated, angry, or well… bitchy.

While some men are believed to suffer from it, it’s called “Resting Bitch Face” and not “Resting Person Face” for a reason. Culturally, women are expected to appear more pleasant. Hence why any woman who has ever walked down a street has heard at least one man—or 20—shout, “Come on, give me a smile!”

While science continues to investigate why some people’s neutral expressions appear more friendly than others, the larger conversation about RBF has begun to explore the impact such facial expressions (or lack of expression?) can have on women’s career aspirations. According to The New York Times, plastic surgeons have been fielding inquiries from women regarding how to fix their “permafrowns.” Most telling, the Times noted: “But, after calling around the state asking more than a dozen C-suite women in multiple industries to weigh in on the subject, we noticed one thing: No one ever scoffed or even asked, ‘Why would this matter?’”

Because unfortunately, we all know that if you’re a woman, it does matter. Much more than it does if you’re a man. But RBF is not the only landmine we ladies must contend with when it comes to our faces. Research has found that part of why women have more trouble negotiating raises, for example, is that doing so affects how likable the woman is seen as being, and being viewed as unlikable is a greater hindrance to women in the workplace than men.

Which means Clinton had a hell of a balancing act to pull off Monday. She had to convey competence without squandering whatever likability she has managed to accrue with voters. But most of all, she had to do all of that while not conveying on her face what she—and many of us—really thought about what Donald Trump was saying: namely that much of what came out of his mouth was either offensive—or crazy. Crazy as in not rooted in fact.

One of the most telling moments was when Trump began speaking about the effectiveness of New York City’s “stop and frisk” policy. It was deemed unconstitutional because it was executed in a manner that was discriminatory and ineffective. Those are facts. More than 80 percent of those stopped were black and Latino men. More than 80 percent of all men stopped were completely innocent.

As a black journalist sitting with a predominantly black audience at a debate screening I hosted at the famed Apollo Theater in Harlem, the outrage was palpable as Trump went on and on about how dangerous our communities are, and how effective this discriminatory policy was—even though it wasn’t. Clinton—having actually served as an elected official representing New York, and whose husband’s post-presidential office had been in Harlem—knew that not only what he was saying was wrong but, frankly, horrible. Consider what it would feel like to be in a joint job interview, where the other candidate spent minutes telling the recruiter the sky is red. What would your face look like? Because that’s essentially what happened during that exchange and yet Hillary’s face never became a blinking neon sign screaming “What he’s saying is crazy.”

Instead of death by a thousand cuts, she dispatched him with an evening of “RPF”: Resting Pleasant Face. No matter what he said—or did, such as interrupting her more than 50 times—she kept a look on her face that said calmy and clearly, “I am a serene, sane, pleasant adult.” Which is not easy to do when you not only disagree with what is coming out of someone’s mouth but actually find it offensive.

Clearly many women related to Clinton’s experience. The most popular article on the PBS website as I write remains one titled: “For many women, watching Trump interrupt Clinton 51 times was unnerving but familiar.” We’ve all been there—with a male boss or colleague. But speaking from experience, not all of us have managed to hide our contempt the way Clinton did.

She even laughed occasionally—not in a way that seemed disdainful but genuinely amused. On this point, she had her critics. Apparently there is a fine line between being the unlikable, unsmiling, unattractive woman, and smiling too much. At least according to men. (And as we all know from catcalls to the corner office, they make the rules about how women are supposed to look and behave—because we certainly wouldn’t want men to feel uncomfortable.) According to Fox News’s Brit Hume, as per The Washington Post, Trump “looked annoyed, put out, uncomfortable.” Clinton “looked composed, smug sometimes, not necessarily attractive.”

Another high-profile Republican viewer, former Bush spokesman Richard Grenell, tweeted, “Hillary’s condescending smile is NOT likable.”

I’m sure if Clinton hadn’t smiled at all during the debate these men most definitely would have given her much higher marks. (Yes I’m being sarcastic—which is certainly risky because it’s yet another thing that some men don’t find appealing in a woman.)

Over the years I’ve received my share of lectures for conveying my displeasure, and occasional disdain for some of the comments directed my way by others—including occasionally condescending men, including on television—on my face. But thankfully I’ve never had to worry about perfecting my facial expression before 100 million people during the biggest job interview of my life.

The fact that Hillary Clinton not only kept her cool during the debate—but kept her game-face—should serve as a model to women everywhere. Including some women who may not like her enough to vote for her, but who will still benefit from her changing the way we think and talk about the images of strong, competent women in the political sphere and beyond.