The U.S. Republican presidential hopeful Newt Gingrich leads the GOP field in a new national poll, four points ahead of the long-time front-runner Mitt Romney.

Twenty-six percent of likely Republican voters support the former House Speaker as the party's nominee, up 16 points since early November, according to the Quinnipiac University poll released Tuesday. He was followed by Romney, the former Massachusetts governor, with 22 percent of support, down one point from the previous poll.

Gingrich also enjoys a comfortable edge over Romney in hypothetical head-to-head match-up, 49 percent to 39 percent.

This was the latest survey that demonstrated Gingrich's surge in recent weeks. A Gallup poll released Monday showed that Gingrich and Romney are neck-in-neck in the race for GOP nomination. Among Republican registered voters, Gingrich is the choice of 22 percent and Romney at 21 percent.

In a CNN-ORC poll released Monday, Ginrich leads the Republican field with 24 percent of support, followed by Romney with 20 percent.

Gingrich's rise was in large part attributed to his good performances in GOP presidential debates, in which he successfully portrayed himself as serene, mature and knowledgeable. That's also one of the selling points on his campaign trail.

"If you stop and ask yourself: it's October of 2012, President Obama is spending one billion dollars beating up the Republican candidate and you get to the debates, who do you want to have debate Obama to draw clarity between the various lies they will be telling and the truth," the former speaker told a crowd Monday in New Hampshire. "I think most people end up thinking I'm probably a better debater than my friends are."

Gingrich, who was almost left dead by pundits this summer after the exodus of his campaign staff, surged to the top-tier of the GOP field after businessman Herman Cain collapsed amid sexual harassment allegations, and is now seen as the new "anybody-but- Romney" candidate.

The Quinnipiac University poll also showed Cain's continuous decline triggered by the sexual scandal and worsened by his gaffes in recent primary debates and interviews. He fell from 30 percent early this month to only 14 percent in the latest poll.

Texas Governor Rick Perry and House Representative Ron Paul each took 6 percent, followed by Congresswoman Michele Bachmann at 4 percent. Former ambassador to China Jon Huntsman and former Senator Rick Santorum of Pennsylvania took 2 percent each.