Fox News anchors moderate the first prime-time Republican presidential debate Aug. 6, 2015, in Cleveland. From left are Chris Wallace, Megyn Kelly and Bret Baier. The top 10 GOP candidates were selected to participate in the debate based on their rank in an average of the five most recent national political polls. Chip Somodevilla/Getty Images

Walking onstage to the Fox News-hosted debate Thursday, the 10 ranking Republican presidential candidates might not have been prepared for a night of sharp, pointed, confrontational questions. The conservative channel has earned a reputation as a megaphone for the GOP under the direction of former Republican media consultant and spin doctor Roger Ailes.

But from the very start, moderators Megyn Kelly, Chris Wallace and Bret Baier made it clear they would take no prisoners.

The biggest target, of course, was bright and orange: GOP front-runner and ex-reality TV star Donald Trump. The debate kicked off with a question aimed right at him: Baier asked the field to say whether they would support the eventual Republican nominee without running as an independent and potentially splitting the party.

Trump refused to take the pledge.

"Mr. Trump, to be clear, you're standing on a Republican primary stage," Baier said. "An independent run would almost certainly hand the race over to Democrats and likely another Clinton. You can't say tonight that you can make that pledge?"

Trump, who has enjoyed the most coverage out of any of the candidates on Fox News (and everywhere else), was treated to a wave of boos. They may have been the first boos he heard since he started running.

But of all the moderators, Kelly stole the show. She cut straight to the bone with questions about sexism, waterboarding, and the Iraq War, earning praise from liberals and conservatives alike.

The hottest moment came when she confronted Trump, who managed to smirk throughout, over his past comments calling women "fat pigs," "dogs," "slobs," and "disgusting animals."

"Only Rosie O'Donnell," Trump responded.

"You once told a contestant on 'Celebrity Apprentice' it would be a pretty picture to see her on her knees," Kelly said. "Does that sound to you like the temperment of a man we should elect as president?"

Despite all the coverage of Trump's wild remarks by liberals in the media and elsewhere, Kelly was the first person to confront him with all of his disparaging remarks against women. And progressives took to Twitter to declare that they loved it.

Meanwhile, Wallace sounded exasperated trying to wrestle an answer from candidates such as Scott Walker, John Kasich and Marco Rubio about their actual policy plans to address illegal immigration. He zeroed in on Walker, the Wisconsin governor who has come a long way from once supporting a path to citizenship for illegal immigrants to the absolutist, anti-"amnesty" ideology of his fellow GOPers.

"Other than politics, could you explain why in the past two years you've changed your position on the path to citizenship, and are there other positions we shouldn't hold you to?" Wallace asked.

"I acknowledged that," Walker responded. "I said I actually listened to the American people. And I think people across America want a leader who’s actually going to listen to them."

(For his part, Trump reminded the moderator: "If it weren't for me, Chris, you wouldn't even be talking about illegal immigration, if it weren't for me.")

Kelly dragged former Florida Gov. Jeb Bush back into a question that he bombed on earlier this year: whether or not, knowing what we know now, he would have sent the United States into Iraq to topple Saddam Hussein and rebuild the country from scratch. Bush spent a whole week in May stumbling through the Iraq issue, earning mockery from both liberals and conservatives -- and it was Kelly who posed the question in the first place.

"For days on end in this campaign, you struggled to answer that question," she reminded Bush.

"I remember, I remember, Megyn," Bush said with a laugh.

"I remember, too," Kelly said. "And of course, ISIS is now thriving there."

Fox's audience, from those in the crowd to GOP pollster Frank Luntz's focus group interviewed after the show, were along for the ride. Luntz was quick to note that his focus group of conservative Republicans appreciated the questions, learned a lot, and turned on Trump after his treatment of Kelly.

"Donald Trump’s crack at Rosie O’Donnell sent my focus group numbers soaring," Luntz tweeted. "His jab at @MegynKelly sent them plummeting."

And so ended the first GOP debate: fair, balanced, and brutal.