Sen. Kirsten Gillibrand (D-N.Y.) has a single-digit lead over her little-known Republican opponent and less than 50 percent of likely voters say in a poll released Thursday that they plan to vote for her.

Gillibrand tops her Republican opponent, former state Rep. Joseph DioGuardi 48-42 percent in the latest Qunnipiac poll, its first of likely voters this cycle.

Both candidates enjoy more than 80 percent support from their own parties, but independents narrowly favor DioGuardi 42-41 percent.

The poll comes one day after a Quinnipiac poll showed Tea Party-backed gubernatorial candidate Carl Paladino within 6 points of Attorney General Andrew Cuomo, the heavily favored Democratic nominee.

Republicans had difficulty recruiting a top-tier challenger to run against Gillibrand, an appointed senator who was viewed as vulnerable by many political observers.

Even though the poll shows Gillibrand in a closer race than some expected, the result also shows ample room for movement. Gillibrand has a 49-37 percent job approval rating and a 43-32 percent favorability rating, but 61 percent of likely voters say they have not heard enough about DioGuardi to form an opinion of him.

"New York has two Democratic U.S. senators, and the numbers suggest it's likely to stay that way," Quinnipiac University polling director Maurice Carroll said. "Sen. Charles Schumer has a commanding lead, and Sen. Kirsten Gillibrand is closing in on the magic 50 percent point. But DioGuardi makes a race of it against her, even though three-fifths of New Yorkers don't know much about him."

A Siena poll released later Tusday showed both Cuomo and Gillibrand in much better shape. The survey of registered voters, not likely voters, has Cuomo leading Paladino by 33 points and Gillibrand leading DioGuardi by 24 points.

The Quinnipiac poll, which surveyed 751 New York State likely voters from Sept. 16-20, has margin of error of 3.6 percentage points.

-- This post was updated at 10:32 a.m.