Updated

Donald Trump was the unrivaled lightning rod at Thursday’s Republican presidential debate, but the prime-time showdown made clear he’s not the only fighter on the stage – or in the race.

New Jersey Gov. Chris Christie reclaimed his reputation as a tough-talking executive, blasting his rivals for their positions on domestic surveillance and entitlements. Kentucky Sen. Rand Paul traded barbs with several candidates, including Christie.

Retired neurosurgeon Ben Carson, former Arkansas Gov. Mike Huckabee and Wisconsin Gov. Scott Walker, among others, also scored their moments. Meanwhile, one-time front-runner former Gov. Jeb Bush found himself on defense several times and largely avoided tangling with Trump on the Fox News/Facebook stage.

Perhaps the most fiery moment came in an exchange between Christie and Paul. Long-simmering tension between the two exploded when Christie stood by his criticism of the senator for opposing NSA bulk collection of Americans’ phone data.

Paul said he’s “proud of standing for the Bill of Rights,” but Christie called his stance “completely ridiculous” – suggesting he wants to cherry-pick only some data.

“When you’re sitting in the subcommittee just blowing hot air about this, you can say things like that,” Christie said.

Paul fired back: “I know you gave [President Obama] a big hug, and if you want to give him a big hug again, go ahead.” Christie said the hugs he gave were to the families of 9/11 victims, and then accused Paul of playing “politics,” by using videos of floor speeches to raise money.

Though several rivals stood out, Trump did not hold his fire, either.

Trump, the billionaire businessman front-runner, sparred at the outset of the debate with Paul after refusing to pledge to support the eventual GOP nominee if it’s not him and to swear off an independent run.

“I will not make the pledge at this time,” Trump said.

Paul accused him of “hedging his bet on the Clintons.”

A big question going into the debate was whether Bush would aggressively challenge Trump and try to knock him off his perch.

But he would only go so far as to question Trump’s tone, calling his language “divisive.” Hours before the debate, Politico ran a story saying Bush recently told a donor he thinks Trump is a “buffoon” and a “clown.” Asked about that report on stage, Bush denied it.

“It’s not true,” Bush said.

Trump then called Bush a “true gentleman.”

Never breaking his calm and collected demeanor, Carson also reminded voters in his closing remarks of a professional background that separates him from the rest: “I’m the only one to separate Siamese twins.”

Florida Sen. Marco Rubio landed laughs when, asked about his faith and God, he said: “I think God has blessed us, he’s blessed the Republican Party with some very good candidates. The Democrats can’t even find one.”

The sparks flew at the second of two kick-off debates, hosted by Fox News and Facebook in conjunction with the Ohio Republican Party.

The seven other Republican hopefuls spent much of the first debate doing their best to hammer home the message that Hillary Clinton represents four more years of Obama. In the earlier debate, the candidates largely avoided sparring with each other and instead trained their fire on the Obama years -- with promises to roll back ObamaCare and undo the Iran nuclear deal.