The billionaire real estate mogul delivered an unforgettably explosive performance Thursday night. He repeatedly attacked his rivals on stage, jousted with the moderators, drew jeers and laughter from the audience with his typically colorful language and, true to form, refused to apologize for anything.
The nine candidates flanking Trump at the prime-time debate appeared emboldened at times by Trump's bluster and, at other moments, amused by the conduct of the GOP's current frontrunner. Meanwhile, the three moderators faced a difficult task: no matter how hard they tried to corner Trump on his inconsistencies and vulnerabilities, the businessman never gave an inch.
The challenge for all of Trump's competition during the two-hour debate hosted by Fox News was to step out of Trump's shadow. The stakes were particularly high for former Florida Gov. Jeb Bush, who has been trailing Trump in the national polls and has suffered a series of missteps in recent weeks. Bush had an even performance, giving solid answers on his weak spots: immigration and Common Core.
Candidates like Sens. Marco Rubio of Florida or Wisconsin Gov. Scott Walker accomplished an important feat for first-time, mid-tier candidates: they stayed clear of any major blunders.
Others lower down on the totem poll who barely made the cut to participate in the 9 p.m. debate, like Ohio Gov. John Kasich and New Jersey Gov. Chris Christie, injected fresh energy into their stalled campaigns. Kasich in particular had a strong debate, drawing an enthusiastic welcome from his home-state audience.
The high-drama began Thursday within the very first moments of the debate.
Trump drew audible boos from the stadium when he declined to rule out a third-party presidential run -- a move that could seriously complicate the GOP's bid for the White House.
"I mean, this is what's wrong. He buys and sells politicians of all stripes. He's already hedging his bet on the Clintons, OK?" Kentucky Sen. Rand Paul cut in.
Trump responded by chastising the country for being too "politically correct."
"I've been challenged by so many people and I don't frankly have time for total political correctness," Trump quipped.
Moderator Megyn Kelly challenged Trump on some of his past comments about women. "You call women you don't like fat pigs, dogs, slobs and disgusting animals," she said.
Trump quickly responded: "Only Rosie O'Donnell," sparking laughter from the audience.
Immigration loomed large at the debate -- an issue that Trump claimed full credit for bringing to the nation's attention.
"If it weren't for me, you wouldn't be even talking about illegal immigration, Chris," Trump said to Fox host Chris Wallace. "This was not a subject that was on anyone's mind until I brought it up at my announcement."
Bush, addressed the issue by stressing that he did not support "amnesty."
"We need to be much more strategic on how we deal with border enforcement, border security," Bush said. "We need to eliminate the sanctuary cities in this country. It is ridiculous and tragic that people are dying because of the fact that local governments are not following the law."
Bush's stance on what to do about the millions of undocumented immigrants in the country has dogged him, but his answer Thursday seemed to pass muster with the audience.
Trump was smack in the center of the debate lineup. The lower tier of presidential contenders had their brief moment in the sun earlier Thursday at a separate debate in which Carly Fiorina delivered a memorable and polished performance.
High-stakes moment for Trump
But the prime-time debate was easily the main attraction, and served as a particularly high-stakes moment for Trump. His early dominance has both stunned -- and aggravated -- members of his own party. National Republican leaders have at times seemed unsure of what to make of the fact that such a no-filter politician with no obligations to the party could unexpectedly become the GOP's standard-bearer.
The open contempt for Trump was on full display starting with the 5 p.m. debate. Lesser-known contenders including former Texas Gov. Rick Perry and Fiorina slammed Trump, blasting the celebrity New Yorker's conservative credentials and friendly relationship with Hillary and Bill Clinton.
"I talked about Donald Trump from the standpoint of being an individual who is using his celebrity rather than his conservatism," said Perry, who has positioned himself as one of Trump's biggest antagonists on the trail. "How can you run for the Republican nomination and be for single-payer health care?"
For his part, Trump found plenty of openings to mock his rivals. When asked to address some of his businesses that went bankrupt, Trump pivoted to the financial woes of New Jersey -- a clear swipe at New Jersey Gov. Christie.
"I had the good sense to leave Atlantic City, which by the way, Caesars just went bankrupt," Trump said, then gestured to Christie: "Chris can tell you."
Later in the debate, Bush cautioned that Trump's "divisive" language could be detrimental to the Republican Party.
"We're going to win when we unite people with a hopeful, optimistic message," he said.
A Bloomberg survey released Tuesday had Trump at 21%, handing him a double-digit lead over both Bush, who was at 10%, and Wisconsin Gov. Scott Walker, who was at 8%.
The other candidates on the prime-time debate stage were Mike Huckabee, Ben Carson.
It wasn't only Trump who had tense exchanges with his rivals.
At one point, Christie and Paul tumbled over the issue of data collection after Paul said he was proud to stand for the Bill of Rights.
"Megyn, that's a completely ridiculous answer," Christie snapped. "I want to collect more records from terrorists, but less records from other people. How are you supposed to know?"
"You get a warrant!" Paul responded.
Christie shot back: "You know, when you're sitting in a subcommittee just blowing hot air, you can say things like this."
When Paul criticized Christie for hugging President Barack Obama several years ago, Christie went for the jugular: "Senator Paul, you know, the hugs I remember are the hugs that I gave to the families who lost their people on September 11th."
Democratic presidential frontrunner Hillary Clinton was another frequent target at both debates. Describing her as "secretive" and "not trustworthy," candidates at the earlier event slammed her on issues ranging from foreign policy to her use of a private email server at the State Department.
South Carolina Sen. Lindsey Graham also took a more personal shot at Clinton, criticizing her now-infamous comments that she and Bill were "dead broke" after leaving the White House.
"I know the difference between flat broke -- apparently she doesn't," he said. "Hillary, I'll show you flat broke. That's not it."