After weeks of trading barbs over each other’s immigration positions while remaining vague on their own, Sens. Marco Rubio (R-FL) and Ted Cruz (R-TX) finally had their big, climatic showdown on the so-called “amnesty” question, with Rubio in some respects turning the tables on Cruz.

Going into Tuesday debate, immigration had been a weakness for Rubio among conservative voters and Cruz had been dogging him on the issue from afar on the campaign trail. Ultimately, Rubio didn’t have to give up much — he landed on supporting green cards for undocumented immigrants — but he was able to put Cruz on the spot for his own waffling on the issue.

Rubio’s involvement in the failed 2013 “Gang of Eight” immigration bill had long been viewed as a vulnerable spot for him among hard-right primary voters, a vulnerability that only increased as frontrunner Donald Trump has amped up the rhetoric on immigration.

Sure enough, Sen. Rand Paul (R-KY) used a question about national security to attack the Florida senator for having “more of an allegiance to Chuck Schumer and to the liberals than he does to conservative policy.”

But Paul was really only taking a page out of the Cruz playbook, as the Texas conservative used immigration as his opening shot in the ongoing Cruz-Rubio campaign trail spat.

When debate moderator Dana Bash asked Rubio point blank where he stood on the substance of the bill, particularly its pathway to citizenship, Rubio tried the sort of equivocating that he’s used to avoid the question in the past: Americans don’t trust the federal government to enforce immigration laws, that security measures must be increased, and that only then could undocumented immigrants receive work permits.

But pressed further, he finally landed on his position:

“I personally am open to allowing people to apply for a green card,” Rubio said. “That may not be a majority position in my party, but that’s down the road.”

Bash turned the debate to Cruz, asking him about how his position compares to Rubio’s. The Texas senator did not turn down another opportunity bash Rubio’s involvement in the immigration legislation as a national security threat.

Allowed to respond to Cruz, Rubio said he was “puzzled” by Cruz’s “attack on this issue,” accusing Cruz of supporting a pathway to citizenship as well as an increase to legal immigration. When Cruz rebutted the claim, Rubio urged Bash to press whether Texas senator would rule out legalizing people here illegally, which she did.

“I have never supported legalization and I don’t intend to support legalization,” Cruz said, referring to citizenship for current undocumented immigrants.

While conservatives will surely continue to jump on Rubio for supporting “amnesty,” Cruz’s admission that he could cost him as well, which could explain Rubio’s grin once Cruz clarified his stance.

It was only a few weeks ago that Cruz was refusing to even define “amnesty” — even in the context of his opposition to it — perhaps out of fear of being boxed in.

And the Rubio campaign was ready for Cruz’s remark. Minutes later, it blasted a memo to reporters arguing that Cruz had previously been open to giving undocumented immigrants legal status.