Massachusetts state Sen. Scott Brown (R) has defeated state Attorney General Martha Coakley (D) in the hotly-contested race to fill the late Sen. Edward Kennedy’s (D) seat.

With 99 percent of precincts reporting, Brown had 52 percent to Coakley’s 47 percent. Independent candidate Joseph L. Kennedy (no relation to the late Senator) had 1 percent. The Associated Press has called the race for Brown and Coakley called the state senator to concede.

Brown’s victory, which is likely to be viewed as one of the biggest political upsets of all time, will strip Senate Democrats of their 60-seat super majority when Brown is sworn in. Brown’s victory must be certified by the state before the Senate will seat him, a process that will take at least 10 days. Republicans, however, may push to seat Brown right away, based on unofficial results.