ALBANY — New York lawmakers, including one representing Niagara Falls, narrowly voted to legalize same-sex marriage Friday, handing activists a breakthrough victory in the state where the gay rights movement was born.

New York will become the sixth state where gay couples can wed and the biggest by far.

Gay rights advocates are hoping the vote will galvanize the movement around the country and help it regain momentum after an almost identical bill was defeated here in 2009 and similar measures failed in 2010 in New Jersey and this year in Maryland and Rhode Island.

Though New York is a relative latecomer in allowing gay marriage, it is considered an important prize for advocates, given the state’s size and New York City’s international stature and its role as the birthplace of the gay rights movement, which is considered to have started with the Stonewall riots in Greenwich Village in 1969.

The New York bill cleared the Republican-controlled state Senate on a 33-29 vote. The Democrat-led Assembly, which passed a different version last week, is expected to pass the new version with stronger religious exemptions and Democratic Gov. Andrew Cuomo, who campaigned on the issue last year, has promised to sign it. Same-sex couples can begin marrying beginning 30 days after that. The passage of New York’s legislation was made possible in two Republican senators who had been undecided.

Sen. Mark Grisanti, R-Buffalo, who also represents the Falls and portions of Tonawanda, was one of them.

Grisanti, speaking to his colleagues and a packed Senate chamber, said he could not deny anyone what he called basic rights.

An attorney by trade, Grisanti said he examined the issue from a legal perspective and “did the work” of researching the issue.

"I cannot legally come up with an argument against same-sex marriage,” Grisanti said. “Who can say, legally, that they don’t have the same rights that I have with my wife?"

A freshman senator, Grisanti defeated Democrat Antoine Thompson by just 527 votes in 2010. Thompson voted in favor of the gay marriage bill in 2009 and Grisanti ran telling supporters that he would not vote in favor of a gay marriage bill.

Explaining his reversal, Grisanti said, “a person can be wiser today than yesterday.”

Erie County Republican Chairman Nick Langworthy released a statement following Grisanti’s yes-vote, saying he was “disappointed” in the senator’s decision.

The other last-minute yes-vote came from Sen. Stephen Saland, a Poughkeepsie Republican, who voted against a similar bill in 2009, helping kill the measure and dealing a blow to the national gay rights movement.

On Friday, he reversed his position.

“While I understand that my vote will disappoint many, I also know my vote is a vote of conscience,” Saland said in a statement to The Associated Press before the vote. “I am doing the right thing in voting to support marriage equality.”

Gay couples in gallery wept during Saland’s speech.

Other Western New York state Sens. Mike Ranzenhofer, George Maziarz and Patrick Gallivan, all Republicans, voted against the bill. State Sen. Tim Kennedy, a Buffalo Democrat, voted yes.

With one vote to spare, New York’s upper chamber made a powerful statement in the gay rights movement, which has been stalled nationally since the passing of Proposition 8 in 2008, a California ballot initiative that overturned gay marriage legislation there.

As was the case in California for those in opposition to gay marriage, the effects of the law ‘s passage could be felt well beyond New York: Unlike Massachusetts, which pioneered gay marriage in 2004, New York has no residency requirement for obtaining a marriage license, meaning the state could become a magnet for gay couples across the country who want to have a wedding in Central Park, the Hamptons, the romantic Hudson Valley or that honeymoon hot spot of yore, Niagara Falls.

New York, the nation’s third most populous state, will join Connecticut, Iowa, Massachusetts, New Hampshire, Vermont and Washington, D.C., in allowing same-sex couples to wed.

For the five months in 2008 when gay marriage was legal in California, 18,000 same-sex couples rushed to tie the knot there before voters overturned the state Supreme Court ruling that allowed the practice. The constitutionality of California’s ban is now before a federal appeals court.

While court challenges in New York are all but certain, the state — unlike California — makes it difficult for the voters to repeal laws at the ballot box. Changing the law would require a constitutional convention, a long, drawn-out process.

The sticking point over the past few days: Republican demands for stronger legal protections for religious groups that fear they will be hit with discrimination lawsuits if they refuse to allow their facilities to be used for gay weddings.

The climactic vote came after more than a week of stop-and-start negotiations, rumors, closed-door meetings and frustration on the part of advocates. Online discussions took on a nasty turn with insults and vulgarities peppering the screens of opponents and supporters alike and security was beefed up in the capitol to give senators easier passage to and from their conference room.

The night before, President Barack Obama encouraged lawmakers to support gay rights during a fundraiser with New York City’s gay community. The vote also is sure to charge up annual gay pride events this weekend, culminating with parades Sunday in New York City, San Francisco and other cities.