She used to brag about keeping a gun under her bed, but now advocates for gun control.
"She sounded like Annie Oakley and now she's somebody different," Republican Joe DioGuardi said.
DioGuardi was on the attack.
On smoking, she once worked for Phillip Morris, but said she was only a junior lawyer back then.
"Kirsten you say you are for transparency. It's outrageous you could stand there and not the answer the question the way you should," DioGuardi said.
But Gillibrand was ready and ripped her opponent for being pro-tobacco when he was a congressman.
"You chose to vote for subsidies for tobacco farmers and you didn't choose to tax," she said.
"No. I didn't," DioGuardi shot back.
"Look at the record. It's there. That's what transparency is about," Gillibrand said.
On the Obama healthcare bill, DioGuardi said he would repeal it and start over. Gillibrand defended it by slamming her opponent on abortion.
"My opponent doesn't believe in covering women's health care and women's rights. He doesn't support a woman's right to choose," she said.
"This is an indication she wants to follow the Obama administration and just expand the federal government," DioGuardi said.
They clashed on a mosque planned near ground zero, on the war in Afghanistan and on whether she visits enough of New York.
"I've been all around this state. She's been AWOL," he said.
On reforming Wall Street, she voted in favor of the latest bill. He calls it too much.
"Not with over-regulation, the way you and Barack Obama have been pushing," he said.
"The worst thing that could happen to this city and this country is the collapse of our financial market, another AIG," she fired back.
At one point things got nasty, when he accused her and her husband of selling stock to avoid a loss in the mortgage crisis.
"I find your personal attacks on a family member very offensive," she said.
And on tax cuts, DioGuardi said everyone should enjoy them. Gillibrand said not the wealthy.
"My opponent wants to give a tax break to the top two percent of the Americans who are the wealthiest among us," she said.
The two candidates plan a second debate on Thursday in Troy.
