New York City Public Advocate Bill de Blasio has taken the lead in the Democratic primary for New York mayor, as Anthony Weiner has faded from contention, according to a new Quinnipiac University poll.

The poll shows Weiner dropping to a distant fourth place, with just 10 percent of the vote. Less than a month ago, Weiner led the field in Quinnipiac polling.

As Weiner has dropped, both de Blasio and 2009 nominee Bill Thompson have benefitted. Erstwhile frontrunner and City Council Speaker Christine Quinn, meanwhile, has not.

The poll shows de Blasio at 30 percent, Quinn at 24 percent and Thompson at 22 percent. A fifth candidate, city Comptroller John Liu, is at 6 percent.

Just as ominous for Weiner is the fact that he almost definitely couldn't win a runoff. If no candidate wins more than 40 percent of the vote, the race goes to a two-person runoff -- Weiner's only real shot at victory. But 51 percent of people say they would never vote for Weiner under any circumstances -- up from 28 percent last month -- meaning it's highly unlikely he could win a two-person runoff.

De Blasio also leads both Quinn and Thompson in a runoff, according to Quinnipiac. He leads Quinn by 16 points and Thompson by nine.

If Weiner somehow made the runoff, de Blasio would lead him 72-22, according to the poll. .