Hours ahead of their first one-on-one debate and just days before the state's primary on Tuesday, a new poll shows Bernie Sanders with a 20-point lead over Hillary Clinton in New Hampshire.

The NBC News/Wall Street/Marist poll released Thursday shows the Vermont senator getting the support of 58 percent of likely Democratic primary voters, compared to Clinton's 38 percent. For voters under 30, he holds a very strong lead—76 percent to 24 percent. Sanders also currently has more support among likely women voters, winning that category by 50 percent to 46 percent.

"So far in New Hampshire, it’s all Sanders as Clinton faces an uphill fight," NBC reports pollster Lee Miringoff, director of the Marist College Institute for Public Opinion, as saying.

The new poll results come days after a "virtual tie" between the two in the Iowa caucus, and shows nearly the same results as their poll last week when Sanders held a 19-point lead over his rival.

The square-off airing Thursday on MSNBC is the first of four additional debates the candidates agreed to this week. The debate airs at 9:00 PM ET (8:00 PM Central).