JOHANNESBURG, June 28 (Reuters) - Defending champions Brazil fought back from 2-0 down to beat the United States 3-2 and win the Confederations Cup for the third time after a hugely entertaining final on Sunday.

The U.S., who shocked Spain in the semi-finals, looked set for another huge upset when goals by Clint Dempsey and Landon Donovan put them 2-0 ahead at halftime.

American goalkeeper Tim Howard produced several good saves before striker Luis Fabiano took his tournament tally to five in five games when he scored just after the restart and equalised in the 74th.

Brazil captain Lucio completed the job when he rose superbly to head home an Elano corner six minutes from time.