Third Republican Presidential Debate: The 6 Moments That Mattered

— -- At times it seemed the night was defined not by the candidates’ attacks on each other, but on the moderators who lobbed challenging and, at times, contentious questions at them.

Some fought back and some candidates, including Marco Rubio, John Kasich and Chris Christie, came out looking strong. But others, most notably Jeb Bush, needed a breakout moment that never came.

Here’s a look at the six moments that mattered at the third Republican presidential debate:

1. Rubio and Jeb take off the gloves

They were once friends, but no longer.

Marco Rubio, who considered Jeb Bush a mentor, was first asked about Wednesday’s Sun-Sentinel op-ed that called on him to resign.

He called the paper biased, but Bush, a former Florida governor and a constituent, chimed in, which turned quickly into open warfare.

“Can I bring something up here? I'm a constituent of the senator and I helped him and I expected he would do constituent service which means he shows up to work,” Bush said. “When you signed up for this, this is a six-year term. You should be showing up to term.”

Bush added Rubio should “just resign and let somebody else take the job.”

Rubio jabbed back, saying he supported John McCain’s 2008 campaign and he never complained about his voting record.

“The only reason you're doing it now is because we're running for the same position,” Rubio said. “Someone convinced you attacking me is going to help you.”

2. Ted Cruz vs. The Moderators

Texas Sen. Ted Cruz went for the jugular tonight – but his most vicious assault wasn’t on one of his rivals, it was on the CNBC moderators.

“The questions asked in this debate illustrate why the American people don't trust the media,” Cruz said. “This is not a cage match. Donald Trump, are you a comic book villain? Marco Rubio, why don't you resign? Jeb Bush, why have your numbers fallen?” Cruz added, “How about talking about the substantive issues?”

Cruz was evidently unhappy with the tenor of the questions, which started with the moderators asking each candidate their greatest weakness.

“Nobody believes that the moderators have any intention of voting in a Republican primary,” Cruz added. “The questions being asked shouldn't be trying to get people to tear into each other.”

Later in the debate, moderator Carl Quintanilla noted that he probably wouldn’t be going out for a beer with Cruz. (Cruz offered to buy him a tequila).

3. Kasich launches attacks on Trump and Carson

Ohio Gov. John Kasich had no problem going after frontrunner Donald Trump and Ben Carson right off the bat.

“My great concern is that we're on the verge of perhaps picking someone who cannot do this job,” Kasich said, just days after slamming the two frontrunners on the campaign trail.

“Folks, we got to wake up,” Kasich said. “We cannot elect somebody that doesn't know how to do the job.”

Trump was dismissive of Kasich’s criticism. “He was so nice. He was such a nice guy,” he said. “Then his poll numbers tanked. That is why he is on the end [of the stage.] He got nasty. So you know what? You can have him.”

Kasich, who is averaging just 3 percent in the polls according to CNBC’s debate criteria, used to chair the House Budget Committee.

“I'm the only person on this stage that was actually involved in the chief architect of balancing the federal budget,” he said. “You can’t do it with empty promises.”

4. Donald Trump pushed to the sidelines

For a few sections of the third debate, it was easy to forget that Donald Trump was even on the stage.

For 28 full minutes -- from 8:32 to 9:00 -- the Republican frontrunner for the last three months didn’t utter a word. And apart from a brief battle with John Kasich early on in the debate, the real estate mogul didn’t cause many fireworks on the stage.

And when he did get the chance to talk later in the debate, he denied criticizing Mark Zuckerberg and calling Rubio “Mark Zuckerburg’s personal Senator.” But the attack is included in the immigration plan he released in August.

“Mark Zuckerberg’s personal Senator, Marco Rubio, has a bill to triple H-1Bs that would decimate women and minorities,” the report says.

5. Ben Carson vs. “PC Culture”

The debate moderators were not too popular this evening with the audience, but it was Ben Carson who got huge cheers when he was asked about serving on the board of Costco.

The moderator noted Costco is one of the most “gay friendly brand(s)” because of its domestic partner benefits. He was asked why he would be involved with a company that “seems to have a counter view on matters of homosexuality?”

Carson had a simple answer and it clearly pleased the audience: “Obviously, you don’t understand my views on homosexuality.”

The retired neurosurgeon said he may not believe in same sex marriage, but he “believe(s) that our constitution protects everybody, regardless of their sexual or orientation, or any other aspect.”

“I also believe that marriage is between one man and one woman,” Carson said. “There is no reason why you can't be perfectly fair to the gay community. They should not automatically assume because you believe that marriage is between one man and one woman that you are a homophobe.”

He added that it is the “PC culture “that is “destroying this nation,” seeming to play directly into his base. During the follow up question, the moderator was jeered before he could get the question out.

6. Christie shuts down Bush

Chris Christie may be down in the polls, but tonight he reminded the country of the signature style of the governor of New Jersey. Jeb Bush was asked about fantasy sports and the billions awarded in prize money and whether the federal government should regulate it as gambling. Bush said “effectively it is day trading without any regulation at all” and said “there should be some regulation.” Bush noted it shouldn’t be the federal government who regulates it, but it was too late, Christie pounced.

“Are we really talking about getting government involved in fantasy football?,” Christie asked incredulously. “Wait a second, we have $19 trillion in debt, people out of work, we have ISIS and Al Qaeda attacking us and we're talking about fantasy football? Can we stop?”

Christie continued, “Enough on fantasy football. Let people play, who cares?”

Christie scored another win just moments later when sparring with moderator John Harwood quipping, “No, John, do you want me to answer or do you want to answer? Because -- I got to tell you the truth, even in New Jersey what you're doing is called rude.”

Two breakout moments for a candidate who needed the wins.