President Barack Obama's re-election campaign raised $114 million last month, narrowly beating his Republican challenger Mitt Romney for the first time in four months.

Obama' s total -- the largest haul brought in by either candidate during the 2012 presidential campaign -- was only slightly higher than Romney's campaign, which raised $111.6 million in August. But while Romney has raised upwards of $100 million in June, July and August, last month marks the first time the Obama campaign has surpassed the $100 million mark.

The key to fighting back against the special interests writing limitless checks to support Mitt Romney is growing our donor base, and we did substantially in the month of August, said Obama campaign manager, Jim Messina, in a statement. Fueled by contributions from more than 1.1 million Americans donating an average of $58 -- more than 317,000 who had never contributed to the campaign before -- we raised a total of more than $114 million. That is a critical downpayment on the organization we are building across the country -- the largest grassroots campaign in history.

The Romney campaign did not release its total number of donors in August, but said about 94 percent of its donations came from individuals who contributed $250 or less.

Regaining a fundraising advantage will likely provide another boost for the president, who has enjoyed a polling bump following last week's Democratic National Convention. A Gallup daily tracking poll released on Sunday found Obama leading Romney 49 to 44 percent. 

Gallup isn't the only organization reporting a lead for Obama. The Real Clear Politics average, which showed the candidates in a dead heat even as the DNC began, now shows Obama's advantage climbing to 1.8 points. Meanwhile, a Public Policy Polling survey released on Sunday night found the president has a 5-point lead in the battleground state of Ohio.