Ben Carson Leads Donald Trump 28-20 in New Iowa Poll Carson has gained 8 points in the poll while Trump has lost 7.

 -- Donald Trump’s dominance in Iowa just took a hit.

Neurosurgeon Ben Carson has climbed to an 8-point lead over the real estate mogul in the crucial first-in-the-nation caucus state, according to a new poll this morning from Quinnipiac University. It marks the first time Trump has trailed in an Iowa poll in more than three months.

Carson garners 28 percent support from likely Republican caucus-goers in the Hawkeye state, climbing 8 points over the last month to his highest support there yet. Trump earns 20 percent, dropping 7 points in the last month.

Carson’s new lead in Iowa comes mostly thanks to growing support among women. While Trump and Carson each receive roughly the same amount of support from men, Carson earns 33 percent of women compared to only 13 percent for Trump.

Trump was criticized during the first Fox News debate by moderator Megyn Kelly for referring to women as “slobs” and “fat pigs.” He later reportedly said “"Look at that face! Would anyone vote for that?” about fellow Republican contender Carly Fiorina.

Florida Sen. Marco Rubio is also gaining momentum, climbing 8 points in the last month to reach 13 percent support. Texas Sen. Ted Cruz clocked in at 10 percent, Kentucky Sen. Rand Paul took 6 percent, and former Florida Gov. Jeb Bush and businesswoman Carly Fiorina are at 5 percent. The rest of the field had 3 percent or less.

Carson’s new lead comes as the candidate takes a break from public campaign events to go on a book tour. The neurosurgeon had generated controversy over his comments about gun control and a potential Muslim president before beginning his book tour.

The Quinnipiac poll comes just one day after an ABC News/Washington Post poll showed Trump holding steady, leading Carson by 10 points. And more than four in 10 Republicans nationally think Trump will ultimately win the GOP nomination -– and with good reason: he’s led national polls for more than three months.

Carson’s new lead is bolstered by positive ratings across the board: 89 percent of GOP likely caucusgoers say Carson is honest and trustworthy and 84 percent have a favorable view of him –- both the best in the Republican field. Still, Trump is seen as the best candidate to handle the economy and illegal immigration.

Get real-time updates as this story unfolds. To start, just "star" this story in ABC News' phone app. Download ABC News for iPhone here or ABC News for Android here.