Monday brought the first debate of the presidential season, but it often felt like two separate debates. One, from Hillary Clinton, was wonky, crisp, and polished; if not always inspiring, it was professional and careful. The other, from Donald Trump, was freewheeling, aggressive, and meandering, occasionally landing a hard blow but often substance-less and hard to follow. But the two debates intersected at times, sometimes raucously, as Trump repeatedly broke in to interrupt Clinton.

It was a commanding performance from the Democratic nominee. Clinton delivered a series of detailed answers on subjects ranging from race to the Middle East to tax policy. Meanwhile, she delivered a string of attacks on Trump, assailing him for stiffing contractors, refusing to release his tax returns, fomenting birtherism, and caricaturing black America. She stumbled only occasionally, but left few openings for Trump. She remained calm and often smiling as Trump repeatedly attacked her and interrupted her answers—doing it so often that moderator Lester Holt, often a spectral presence at the debate, finally cut in twice in short order to chide him. (Vox counted 40 instances; Clinton made some of her own interruptions, but fewer.) Clinton displayed a sort of swagger perhaps not seen since her hearing before Congress on Benghazi.

The Republican, on the other hand, was erratic, vague, and frequently appeared rude. Where Clinton offered sometimes dull policy prescriptions, Trump stuck to description, diagnosing problems—offshoring of jobs, violence in Chicago, the decay of American infrastructure—but providing nearly nothing in the way of solutions to them, even when pressed by Holt. He cut into Clinton’s answers, interruptions that she seemed almost to welcome because of the contrast they helped draw. Trump seldom stuck to one topic in an answer. A question about why he hadn’t released his tax returns somehow ended with a diatribe about the quality of American airports. (That support for infrastructure improvement was one of the few moments that won the praise of progressive commentators.) He yelled, he scowled, and, somewhat peculiarly, he sniffled through the 90-minute contretemps.

Trump seemed early on to be trying to be solicitous. “Secretary Clinton—is that OK? Yes? Good. I want you to be happy, it’s very important to me,” he said, with a faint smirk. But soon he couldn’t resist cutting in. Clinton assailed Trump for cheering on a housing bust, saying that 9 million Americans lost their jobs. Rather than deny it, Trump boasted, “It’s called business!” As the debate went on, Trump seemed to get more and more peevish. Ahead of the debate, Trump advisers told reporters that he was not preparing extensively, and while there was some speculation that they might simply be depressing expectations, it showed. By the end of the night, he looked as shell-shocked as Barack Obama at the end of the first 2012 debate against Mitt Romney.

That isn’t to say that Trump didn’t get a few good licks in. Employing the improvisatory, pugilistic style that served him well in the GOP primaries, he jabbed at her on several favorite topics. He worked hard to tie Clinton to NAFTA, the 1990s free-trade agreement overseen by President Bill Clinton. It’s a major topic for Trump, who has found it resonates well with white-working-class voters in the Rust Belt. Having connected her with that, Trump argued that Clinton was dissembling in her opposition to the Trans-Pacific Partnership and would reverse her stance once in office.

He also assailed Clinton for her use of a private email server while secretary of state, and mentioned her invocation of the term “superpredator” during 1990s crime discussions, a term advocates have called racially coded and for which Clinton has apologized.

But the night was Clinton’s. Her jabs landed time and again. (A few flat one-liners were a different matter.) As the debate ended, for example, she told the story of Alicia Machado, a former Miss Universe who says she became a citizen to vote against Trump. Trump tried to cut in, asking where she got the story. She also worked at length to tie Trump to the idea of trickle-down economics, a connection he readily accepted. “The wealthy are going to create tremendous jobs,” he said.

She also pressed hard on why Trump had not released his tax returns. “First, maybe he’s not as rich as he says he is. Second, maybe he’s not as charitable as he claims to be,” she said, and added that he might be heavily leveraged. Then she added, “Maybe he doesn’t want all of you to know that he’s paid nothing in federal taxes.” It was bold speculation, but Trump did little to rebut it. He said that he could not release his taxes until an IRS audit was complete, although the IRS has said he is free to release his returns at any time.

Clinton was aided, at times, by Holt, who asked Trump several pointed questions. He forced the Republican to defend his espousal of the “birther” lie against Barack Obama, attempting to falsely blame Clinton and claiming that he’d been satisfied once Obama released his long-form birth certificate in 2011. (In fact, Trump continued to push birther theories for years afterward, only disavowing them earlier this month.) Later, when Trump tried to claim that he had opposed the war in Iraq, Holt repeatedly contradicted him. (Trump called the oft-proven fact “a mainstream media nonsense.”) On balance, Holt asked Trump more pointed questions that he did Clinton, though Trump also, to be blunt, has more to answer for. The crowd, instructed to be quiet, mostly sat on its hands for the debate, but as the end approached, members got into the act, too, loudly cheering Clinton on a couple of occasions.

But Clinton was also aided by Trump. In one of the more confusing moments of the evening, he said that Clinton had “been fighting ISIS your entire adult life.” The group dates back to 1999 by the most liberal definition. When Holt asked about race and policing in America, Trump delivered a version of a spiel from his stump speech, describing the squalor of inner-city crime and suggesting that stop-and-frisk could help. Clinton criticized the answer, saying Trump failed to understand the vibrancy of black communities, eliciting a noisy “ugh.” He also raised eyebrows by referring to Obama as “your president.” At the end, when asked whether he’d support Clinton if she won, Trump gave a meandering answer, complaining that Clinton’s ads were unfair to him and he didn’t “deserve” it, and saying he’d considered a harsh attack on her family but opted against it. The spiel was strange; Trump seemed to be taken aback by the pressures on a presidential candidate. Only under duress from Holt did Trump say he would support a President Hillary Clinton.

Historically, debates have tended to have little effect on the ultimate result of the election, and little lasting effect on polls. But this was precisely the performance Clinton had wanted. With polls showing a dead heat, Democrats have been beginning to panic, with the pitch increasing ahead of the debate, as supporters wondered whether Clinton could perform, and whether Trump would shoot himself in the foot or manage to appear presidential. It’s also tough to predict the response of voters to a debate, and while Trump performances during the GOP primary were often mediocre at best, he still scored high marks with his supporters.

But Clinton’s delight was barely hidden by the end of the night. When Trump concluded an increasingly angry spiel directed at her—"I have a winning temperament. I know how to win"—the Democrat paused for a brief moment, smiled at the camera, said, “Woo! Okay!” and did a little shimmy before answering. It was the happiest she had looked in public in the last 20 months.

—David A. Graham