New York Gov. Andrew Cuomo and former "Sex and the City" star Cynthia Nixon swapped insults and clashed over policy Wednesday in their only scheduled debate before the Sept. 13 Democratic primary.

The testy, hourlong exchange at Hofstra University featured plenty of interruptions and insults:

Cuomo: Can you stop interrupting?

Nixon: Can you stop lying?

Cuomo did make news during the debate, saying in response to a question about his political future that he plans to serve a full four years and will not run for president if elected to a third term. Cuomo had been considered a potential presidential contender.

Cuomo had been considered a possible presidential contender in 2020, but he brushed off that speculation when asked by a moderator if he would pledge to serve four years if re-elected.

"Yes, yes, yes and yes," he said in response.

Nixon attacked, as predicted. But rather than floating above the fray like the front-runner that he is, Cuomo fought back with surprising fire:

"Only Donald Trump has done less transparency on his taxes than my opponent," Cuomo said.

That was about the actor and activist's taxes, which she files as an S corporation. Cuomo said that makes her so much like the corporations that Nixon rails about.

Cuomo: Are you a corporation?

Nixon: I'm a person.

Nixon attempted to tie Cuomo to the recent conviction of his former top aide, Joe Percoco, on charges that he accepted bribes from companies seeking state economic development funds. She said Cuomo was either complicit or ignorant about what was going on in his administration. "Either corruption or incompetence, which is it?"

Cuomo responded that he didn't know about Percoco's activities and said he would push for greater ethics reforms if re-elected.

On policy, Nixon said progressive politics promoted Cuomo to embrace issues like legalizing recreational marijuana, a charge the governor denies.

The candidates also clashed over some policies Nixon supports, such as the right of public employees to strike, a single-payer state health plan, and reversing a Cuomo executive order that brought state troopers to the city from upstate. Cuomo said he doesn't support the right of public employees to strike, and wasn't as convinced about a single-payer state health plan without action from Washington.

Speaking of Bill de Blasio, neither candidate was eager for the endorsement of the New York City mayor, who Cuomo tied to Nixon, a supporter of his.

Nixon, meanwhile, accused Cuomo of empowering Republicans in Albany and not doing enough to address political corruption, income inequality or New York City's aging subways.

"I'm not an Albany insider like Gov. Cuomo but I think experience doesn't mean that much if you're not good at governing," she said.

Cuomo responded by saying Nixon "lives in a world of fiction" and doesn't understand the challenges of leading the nation's fourth largest state.

"It's about doing. It's about management. This is real life," Cuomo said. "You're in charge of fighting terrorism. You're there in case of fires and floods and emergencies...and today you've got to deal with Donald Trump. You need to know how to do it."

Polls suggest Cuomo has a more than 30 percentage point lead over Nixon, who also trails substantially in fundraising. Observers had predicted that Nixon would attempt to rattle the governor in the hopes that he would misspeak.

While several of Nixon's attacks appeared to irritate the governor, they did not provoke any significant gaffes — such as the governor's comment earlier this month that America "was never that great." Cuomo later said the remark was "inartful."

The Democratic primary winner faces Republican Marc Molinaro, Green Party candidate Howie Hawkins, and independent Stephanie Miner in November. Registered Democrats outnumber Republicans in New York by more than 2-1.