Republican Congressman Dan Donovan and Democratic challenger Max Rose square off in a heated debate in Brooklyn.

This is one of the most watched races in the nation as this is considered a seat the Democrats could flip.

Donovan has held the seat, which encompasses all of Staten Island and part of Brooklyn for three years.

It's the only seat in the city held by a Republican.

Donovan argued that he knows the district better, while Rose touted his military experience.

"He’s not one of us. He doesn’t understand the issues that we’re dealing with. He hasn’t been here. I’ve been here for 62 years," Donovan said.

"So, Congressman I’m sorry I didn’t move here earlier. I was too busy defending my country in Afghanistan,” Rose responded.

The two are set to debate again on NY1, Tuesday night at 7 p.m.