The Manhattan borough president, C. Virginia Fields, will attend a women’s breakfast this morning riding high on a surprise surge in a citywide poll released yesterday. Seen for months as an also-ran, she is running second to the Democratic mayoral front-runner, Fernando Ferrer, and is closing the gap, according to a poll released yesterday.

Mr. Ferrer, a former Bronx borough president, still leads Ms. Fields by 36% to 21%, but the 15% margin is far narrower than in a poll completed March 2, when he held a lead of 40% to 14%, according to the Quinnipiac University survey.

“Any candidate that breaks into Ferrer’s coalition by picking up African-American voters, which is the easiest constituency to see Virginia Fields appealing to, is a problem,” the president of political consultancy the Advance Group, Scott Levenson, said. “In many ways, Fernando Ferrer’s candidacy has tried to mirror the Dinkins coalition of black, Latinos, and progressive whites. Any African-American vote-getter is a real problem for that strategy.”

Analysts said Mr. Ferrer’s poll plunge was self-inflicted. On March 15, while speaking to an assembly of police sergeants, Mr. Ferrer suggested that Bronx prosecutors dealt too harshly with the police officers responsible for the fatal shooting in 1999 at a Bronx apartment building of an unarmed African immigrant, Amadou Diallo.

Mr. Ferrer said the shooting was accidental and not criminal. The problem is that Mr. Ferrer had been on the front lines in 1999 with those who accused the police of using unnecessary force in the case.

The apparent flip-flop clearly resonated with New Yorkers surveyed in the new poll: Of the 46% who said they had heard or read about Mr. Ferrer’s recent remarks, 41% said they thought less favorably of him as a result.

“Obviously the Diallo comments hurt Ferrer,” a Baruch College political science professor, Douglas Muzzio, said. “The question is how acute and chronic a problem it will end up being. What the numbers show is that the subtext of this campaign is ethnicity and race – as it almost always has been in the city’s history.”

Fully 57% of the black voters who had heard of Mr. Ferrer’s Diallo comments said their opinion of Mr. Ferrer had become less favorable, Quinnipiac reported.

A jury acquitted the four police officers involved in the shooting. They said that when they approached Diallo they thought he was reaching for a gun. As it turns out, he was reaching for his wallet.

Ms. Fields has profited from Mr. Ferrer’s misstep.

“All the moves look good for C. Virginia Fields,” the director of the Quinnipiac University Polling Institute, Maurice Carroll, said.

Indeed, the Democratic primary race has begun to shape up as a two-way battle, with Mr. Ferrer and Ms. Fields well ahead of the other Democratic contenders. A Brooklyn and Queens congressman, Rep. Anthony Weiner, had the support of 11% of Democratic voters in the new poll, and the City Council speaker, Gifford Miller – who has raised more money than any of the other candidates at $5.7 million – came in with a scant 10%.

“Virginia has a lot of potential for growth,” her senior political adviser, Joseph Mercurio, said. “As she gets better known she will pick up votes. As we get closer to the primary she is going to get in the run-off and then pass Ferrer.”

There will be a run-off unless the leading candidate polls at least 40% of the vote in the primary.

While the Democrats battle among themselves, Mr. Bloomberg’s poll ratings have barely moved. In a head-to-head match-up with Mr. Ferrer, Mr. Bloomberg lost by 6 percentage points, 46% to 40%, the poll found.

In another match-up, Mr. Bloomberg and Mr. Miller had 40% each. The mayor also ran even with Ms. Fields, with 42% supporting Mr. Bloomberg and 41% backing her. Mr. Bloomberg topped Mr. Weiner by 43% to 35% in the new poll.

Voters split nearly evenly when asked their opinion of the billionaire mayor’s plan to finance his own re-election campaign. While 47% agreed with the statement that the self-financing freed Mr. Bloomberg from the influence of donors, 45% said it gave him an unfair advantage.

Mr. Bloomberg’s approval rating in the poll was 46%, compared to 48% in the poll released March 2.

Quinnipiac polled 1,371 New York City registered voters from March 21 to 28 for the new poll. The margin of error for the whole sample was plus or minus 2.7 percentage points and was somewhat larger for the questions posed only to Democratic voters.

“It is just too early to call this race,” Mr. Levenson, the political consultant, said. “Any of the four Democratic candidates could end up as the nominee. It is early and we have a press corps that hates a front-runner. The next eight weeks are critical on the Democratic side.”

Mr. Mercurio said his candidate would capitalize on her growing momentum. On the eve of the fund-raising breakfast, he said Ms. Fields will do a lot more fund-raising and ultimately will raise the maximum allowed in the primary, $5.7 million.

He also told The New York Sun that Ms. Fields would be announcing a major endorsement Sunday. He declined a request to be more specific.