Billionaire businessman Donald Trump has taken a 10-point lead over Sen. Ted Cruz (R-TX) in Wisconsin in the final hours before the critical primary on Tuesday, a new poll released on Monday afternoon shows.

The bombshell new polling data, from American Research Group (ARG), show Trump’s 42 percent towering over Cruz’s 32 percent in the Badger State. Ohio Gov. John Kasich, for whom it is already mathematically impossible to win the nomination outright before the GOP convention in Cleveland in July, lurks back at 23 percent.

The poll surveyed 400 likely voters and has a five percent margin of error. It was conducted from April 1 to April 3. 54 percent of likely GOP primary voters polled in Wisconsin were men, 46 percent were women.

The Washington Post‘s Chris Cillizza signaled this poll is a “siren” worth looking at.

SIREN: Trump 42, Cruz 32 Kaisch 23 in new Wisconsin poll https://t.co/zpDUXxOCg2 — Chris Cillizza (@CillizzaCNN) April 4, 2016

The results are certainly different than other recent polling that has shown Cruz with a similar lead over Trump. ARG has had mixed results throughout the campaign, finding Trump a point back behind Cruz in Texas. Cruz ended up winning Texas by big margins, well more than 10 points. In Florida, ARG had Trump up 25 points over Marco Rubio–seven points too many. But in New Hampshire, ARG had Trump up 16 points–which was about right. Trump won the Granite State by 20 points.

Marquette and Fox Business polls released last week showed Cruz with 10-point leads over Trump and a smattering of other polling over the last week showed Trump trailing Cruz by around five to seven percent.

It’s unclear if this new ARG poll has any truth to it, but Trump and Cruz have been dueling on the campaign trail over the past few days throughout the state. Both have been barnstorming the state, going all in for Wisconsin.

Earlier on Monday, Trump suggested he might even win Wisconsin—something that was unthinkable just a couple days ago, as everyone thought Cruz would take the Badger State thanks to the endorsement he got from Gov. Scott Walker.

Trump compared Wisconsin to South Carolina—where Gov. Nikki Haley backed Sen. Marco Rubio (R-FL), who has since dropped out of the race. Trump ended up winning decisively in South Carolina.

“It was over. I was going to get killed. The governor of the state, who is fairly popular” endorsed Rubio, Trump said. “The governor supported Marco and I said, ‘That’s bad.’”

“But guess what happened? I won in a landslide. Same thing is going to happen here,” Trump said. “I think the same thing.”

“I don’t know, maybe not,” Trump added.

If Trump does pull off a come-from-behind victory in Wisconsin, it could be devastating to his remaining rivals.

“If we do well here, folks, it’s over,” Trump also said on Monday.

But if Cruz wins, it could cause more damage to Trump—and spark renewed momentum, almost a campaign reset, for Cruz.

Cruz in a CNN interview pushed back on Trump’s prediction, saying that he thinks ultimately “The people of Wisconsin will decide” what happens.