Ted Cruz did well last night’s debate because he knows how to debate—literally.

Though the emerging pundit consensus seems to be that Marco Rubio won the night, Cruz nabbed what was arguably the biggest standout moment of the evening when he squared off with moderator Carlos Quintanilla and questioned the entire premise of the evening’s event. Whether he was conscious of this or not, the senator used a risky and controversial tactic used by high school debates champions the world over to deflate the moderator, win the crowd, and change the tenor of the evening.

The strategy he used is called running a kritik. Depending on what style of debate you’re doing and what league you’re in, kritiks can operate in a host of ways. The basic gist, though, is this: A kritik is an a priori argument, which means it has to be addressed before either side of the debate can move on to talk about anything else. The term “kritik” didn’t come into the common debate lexicon until the ’90s—long after Cruz’s days as a parliamentary debate champion were over. But the strategy existed and was fairly common during his time in academic debate.

Anyway, a debater who runs a kritik (or that style of argument) argues that the entire premise of the debate round is fundamentally flawed. For example, in 2013, two African-American college students—Ryan Walsh and Elijah Smith—won the Cross Examination Debate Association’s national championship in part by deliberately ignoring the tournament’s stated resolution and, according to The Atlantic, arguing instead that “the framework of collegiate debate has historically privileged straight, white, middle-class students.”

In other words, they argued that the entire terms and structure of the debate were unfair. Cruz took a similar approach last night about a third of the way into the CNBC debate. Quintanilla set him off by asking if his opposition to a deal House Republicans recently made to raise spending and avert government shutdowns until March of 2017 shows that the senator was “not the kind of problem solver American voters want?”

At this point, Cruz could have answered the question on its merits, explaining as he’s done a million times already that Americans want someone who will fight to shrink the government, even if it means refusing to compromise with Democrats and risking shutdown. But that isn’t what Cruz did. Instead, he questioned the moral authority of Quintanilla to question him.

“You know, let me say something at the outset,” the senator replied. “The questions that have been asked so far in this debate illustrate why the American people don’t trust the media.”

The crowd cheered.

“This is not a cage match,” the senator continued, reiterating his criticism of CNBC’s management of the event. “And, you look at the questions—‘Donald Trump, are you a comic-book villain?’ ‘Ben Carson, can you do math?’ ‘John Kasich, will you insult two people over here?’ ‘Marco Rubio, why don’t you resign?’ ‘Jeb Bush, why have your numbers fallen?’

How about talking about the substantive issues the people care about?”

Quintanilla sputtered.

“Does this count?” he interjected, over the roaring crowd. “Do we get credit for this one?”

“And Carl, I’m not finished yet,” he continued. “The contrast with the Democratic debate, where every fawning question from the media was, “Which of you is more handsome and wise? Let me be clear. The men and women on this stage have more ideas, more experience, more common sense than every participant in the Democratic debate. That debate reflected a debate between the Bolsheviks and the Mensheviks.”

When student debaters make this kind of argument, one criticism they hear is that they undermine the educational value of the debate round, shifting its focus from the legal or policy issues at hand to loftier, more abstract concerns about language, philosophy, and ethics.

And that’s the criticism Quintanilla leveled at Cruz: How dare the senator redirect the debate to the abstract question of media bias, at the expense of a discussion on the concrete issue of the debt limit?

But Quintanilla’s criticism fell flat. Cruz benefitted hugely from the exchange because the debate audience, judging by their loud and lengthy applause, thought his a priori rejection of the terms of the debate was a valid concern that needed to be aired before the debate itself could continue. And that’s why he won the night.

Don’t believe me? According to Wall Street Journal analysis, that particular moment generated the most conversation on social media—more even than Jeb Bush’s awkward “warm kiss” comment and Donald Trump’s boast about getting the network to cut down the debate time.

And according to CNBC, Cruz was mentioned on social media during the debate more than any other candidate—including nearly 5,000 times in just 60 seconds after he tore into Quintanilla. No other candidate got that many mentions in such a short period of time.

Cruz didn’t just impress the Republican base, though. He also won plaudits from at least one academic debate expert for his strategy.

“One of the things Cruz seems to have learned from his debating experience is that it’s powerful to identify shared assumptions with the audience and then use those shared assumptions to your advantage,” said Kate Shuster, co-director of the Middle School Public Debate Program, who once coached a team to the championship of the National Parliamentary Debate Association.

“It seems like he’s got a good intuition for executing those kinds of tactics,” she added.

And she noted that Cruz’s use of this particular tactic was much more successful than Donald Trump’s. The real estate mogul tried to pull off a similar feat in the first Republican presidential debate, tearing into moderator Megyn Kelly for questioning him about his history of sexist remarks. But Trump’s attack was clumsy and ham-handed, generating as much disgust as approbation. Cruz, on the other hand, knew what he was doing. And from the right, he won universal praise.