Trump fired off a tweet Tuesday night over a pro-Cruz ad that ran in Utah and showed a nude Melania Trump on a fur rug from a GQ shoot taken from her modeling days.

The tweet storm stems from a Facebook ad launched by Make America Awesome, an anti-Trump super PAC founded by Republican strategist Liz Mair.

"Lyin' Ted Cruz just used a picture of Melania from a G.Q. shoot in his ad. Be careful, Lyin' Ted, or I will spill the beans on your wife!", he tweeted Tuesday evening, just minutes before polls closed in Arizona.

Cruz quickly hit back at Trump's threat, explaining that his campaign had nothing to do with the ad. In addition, the senator from the Lone Star State called Trump a "coward" for attempting to smear his wife.

"You probably know by now that most of the things that Donald Trump says have no basis in reality".

"Meet Melania Trump, your next First Lady", the ad reads.

Ted Cruz's response basically was "not today Donald, not today".

Donald Trump and arch-rival Ted Cruz are now in a stand-off over their wives.

Buddy Hield One of Final Four in Running for 2016 Naismith Trophy
James Naismith, the Naismith Trophy is awarded annually to the women's and men's college basketball players of the year. The Spartans senior guard ended his season averaging 19.2 points, 7.8 assists and 7.6 rebounds per game.

Cruz overwhelmingly won Utah with 69.2 percent of the vote, earning 40 additional delegates.

Campaigning for her husband Wednesday in Waukesha, Cruz dismissed those comments and sought to refocus the debate on larger issues.

Earlier, speaking on Fox Business Channel, Cruz used a line that is very similar to one from a movie to defend his wife.

The battle continued on Wednesday with Cruz telling CNN: "He went directly after my wife. We're focusing on our campaign, and we are going to continue to do that", she told reporters while campaigning for her husband in Wisconsin.

The tussle between the two leading Republican candidates began on Tuesday when Trump suggested he might reveal something embarrassing about Heidi Cruz.

She has become one of the campaign's most accomplished fundraisers.

But Stone said, "I don't know what Trump is referring to", when he talks about "spilling the beans".