Fox News was both the host of Thursday night's Republican presidential debate and one of its subjects, as Donald Trump repeatedly goaded the network at his own competing event while Ted Cruz took his lectern and his place as the one to take shots at Fox, a once-unthinkable move for a conservative Republican.

"If you guys ask one more mean question, I may have to leave the stage," Cruz said, after a spat with co-moderator Chris Wallace over how many of Fox's questions were designed to provoke attacks on the Texas senator.

Wallace didn't let it stand.

"It is a debate, sir," he said.

Beltway Twitter crowed.

"Chris Wallace throwing shade at Ted Cruz is everything," tweeted Meghan McCain.

"Chris Wallace is 1000% right. Debates are about sussing out policy disagreements. Which is what the moderators are doing," The Washington Post's Chris Cillizza added.

It's common for Republican politicians to attack the media for asking loaded questions — but less common when aimed at Fox, whose ability to draw attention to red-meat conservative issues was long viewed by Republicans as a corrective to the biases or omissions of the mainstream media.

On Thursday, however, Fox was not only the target of disdain by Trump and Cruz, but also chose to defend itself on traditional journalistic grounds — asserting its independence by refusing to negotiate with Trump over its choice of Megyn Kelly as co-moderator, while also insisting it was a fair and neutral forum where all candidates would get an equal shake.

Top 10 moments of the GOP debate

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The network says there's a stark difference between its news reporters — a category in which the moderators fall — and its opinionated hosts like Bill O'Reilly and Sean Hannity. But the network is still seen by many on the political right as the very voice of heartland conservatism.

But in this campaign, in which Cruz and Trump have largely defined their candidacies against the Washington-based Republican "establishment," Fox has gotten lumped in with the D.C. crowd.

In the first GOP debate last August, Trump became agitated over a question from Kelly about his past statements about women, and he took to the airwaves and Twitter to condemn the anchor. That feud, which Trump fanned for five months, culminated in the candidate's decision to skip Thursday's debate, after Fox not only refused to replace Kelly as moderator but also mocked his unwillingness to face her questioning.

Thus, on Thursday, many viewers found themselves flipping channels between the official GOP debate in Des Moines, Iowa, and Trump's event across town. While Kelly, Wallace and co-moderator Bret Baier were busy questioning the seven candidates on the main stage, Trump was declaring victory in his fight with the network by saying Fox News CEO Roger Ailes had apologized to him for the mocking statement. The network immediately demurred.

Ailes had had three short conversations with Trump, acknowledging his objections to a teasing statement that questioned how he would deal with Iran's ayatollah and Russian President Vladimir Putin, the network said. But it refused to negotiate with the mogul.