First Posted: 9/20/11 02:12 PM ET Updated: 9/20/11 02:41 PM ET
The new survey, conducted by the Democratic-affiliated firm Public Policy Polling (PPP), gives Warren a slight edge over Brown (46 to 44 percent) among likely voters. The two-point gap between the candidates falls well within the survey's 3.5 percent margin of error.
The results come as something of a surprise, given that two live-interviewer polls conducted in late August showed Brown comfortably ahead. A survey conducted by the MassINC Polling Group for Boston radio station WBUR found Brown ahead among likely voters by nine points (44 to 35 percent), while a Boston Globe/University of New Hampshire poll had brown leading among all adults by 19 points (48 to 29 percent).