Elizabeth WarrenElizabeth Ann WarrenRising star Abrams advances in Georgia governor race Progressive rise is good news for Sanders, Warren Juan Williams: Trump gives life to the left MORE raised $5.7 million in the fourth quarter of 2011, a campaign aide confirmed to The Hill.

It’s the best quarter of fundraising by any Senate candidate this cycle, and beats Sen. Scott Brown (R-Mass.) in the fourth quarter by $2.5 million. Warren said she has $6 million cash on hand.

“From all across our commonwealth, people are supporting our campaign and the fight to level the playing field for middle class families,” Warren said in a statement. “With Wall Street lining up against this campaign, already contributing millions and willing to pay any price to try to stop our work, it’s going to take a strong, grassroots effort like this to win.”

On Monday the Brown campaign announced it had raised $3.2 million in the fourth quarter. 

Warren also trounced the incumbent senator in the third quarter, more than doubling his numbers — $3.1 million versus $1.5 million — despite campaigning for only six weeks.

The Brown campaign said it expected Warren's campaign to raise money from "extreme liberal" special interests. 

“Despite our success, we also know that our opponent is getting lots of financial support from extreme liberal special interests and she will likely surpass our numbers,” campaign finance director John Cook said in an email on Monday.

Still, Brown has a considerable war chest, with more than $12.8 million on hand.

Republicans worked to downplay the success of Warren's fundraising, claiming her financing comes from "extreme liberal special interests" from outside of the state she seeks to represent in the Senate.

"As the intellectual founder of the radical Occupy protests, she has a national network of left wing supporters eager to open their wallets to finance her agenda of bigger government, higher taxes and more debt," said Massachusetts Republican Party spokeswoman Alleigh Marré.

Over $600,000 of Warren's campaign cash — including almost $200,000 of her fourth-quarter haul — came from the Progressive Change Campaign Committee, the group said on Wednesday. The liberal PAC was one of Warren's earliest supporters and launched a movement to "draft" Warren into the race in 2011.

A former consumer protection advocate under President Obama, Warren was aggressively courted by Democrats in Washington and Massachusetts to run for Brown's seat.

— This story was updated at 2:49 pm.