NEW YORK — Anthony Weiner lost his lead among seven Democratic candidates for New York mayor in the first poll since he acknowledged engaging in lewd Internet exchanges more than a year after resigning from Congress for similar behavior.

The NBC 4/Wall Street Journal/Marist poll released two days after the revelations showed that Weiner had slipped to a statistical three-way tie for second place, with 16 percent support among registered Democrats, after coming in first with 25 percent in a June 25 poll. City Council Speaker Christine Quinn topped the field in the new survey with 25 percent after receiving 20 percent in the prior poll.

Former City Comptroller William Thompson and Public Advocate Bill de Blasio each drew 14 percent. The Poughkeepsie, N.Y.-based Marist College Institute for Public Opinion based its findings on telephone interviews with 551 Democratic voters. The poll had a 4.2 percentage-point margin of error.

“These new revelations have cost Anthony Weiner the lead in the Democratic field,” said Lee Miringoff, director of the institute. “There’s been a significant erosion in people’s willingness to say he deserves another chance.”

Fifty-five percent had an unfavorable view of Weiner, an all-time high, while 30 percent held a positive one, Miringoff said.

Weiner, 48, has vowed to continue his candidacy after calls for him to drop out from the city’s major daily newspapers, three of his Democratic rivals and the local chapter of the National Organization for Women, which called him “unfit for public office.” He served in the U.S. House of Representatives almost 12 years from a district serving parts of Queens and Brooklyn until his June 16, 2011, resignation.

The survey was taken the day after the gossip website TheDirty.com on July 23 posted exchanges between a woman and a man it said was Weiner. The site showed explicit photos sent under the user name “Carlos Danger,” whom the website identified as the former congressman.

Weiner confirmed the relationship that day in an email, saying, “While some things that have been posted today are true and some are not, there is no question that what I did was wrong.” The behavior, he said, “is behind me.”

Robert Shapiro, professor of political science at Columbia University, called the poll results “striking in the unfavorable views expressed toward Weiner.” Quinn appeared to be picking up support lost by Weiner, Shapiro said.

“If Weiner exits the race, it would appear to benefit her,” he said.

In the poll, City Comptroller John Liu received 7 percent; Bronx pastor Erick Salgado, 2 percent and former City Councilman Sal Albanese, 1 percent. Nineteen percent remained undecided.

Democrats outnumber Republicans in the city by about 6-to-1 among registered voters. If no candidate gets 40 percent in a Sept. 10 primary, the top two finishers in each party will compete in an Oct. 1 runoff.

Thursday’s poll reported that Democrats appear more forgiving toward Eliot Spitzer, who resigned as New York’s governor in 2008 after getting caught consorting with high-price prostitutes. Spitzer, 54, is now running against Manhattan Borough President Scott Stringer to become the party’s nominee for city comptroller.

Spitzer leads Stringer 49 percent to 32 percent among Democrats, including those leaning toward a candidate, with 17 percent undecided. Spitzer has widened his lead since a July 11 Marist poll showed him leading Stringer 42 percent to 33 percent.

Among Democrats, 57 percent say Spitzer would do a good or excellent job as the city’s chief financial officer, responsible for auditing agencies and overseeing about $140 billion in pension-fund assets. Forty percent said Weiner would do an excellent or good job as mayor.

“Spitzer has been given much more leeway than Weiner,” Miringoff said in a telephone interview. “It’s a very different set of perceptions among Democrats concerning Spitzer compared with Weiner.”

Mayor Michael Bloomberg, founder and majority owner of Bloomberg News parent Bloomberg LP, is barred by law from seeking a fourth term.