After a goalless stalemate during regulation time at the Kanteerava Stadium, Bengaluru FC took a 97th minute lead when the talismanic Indian captain converted a free-kick.
Sahal Abdul Samad had put the Blasters in front in the 23rd minute before Barreto returned to score against his former club with an equaliser in the 48th minute.
Kerala Blasters, who had already won the first leg 1-0, drew the second leg 1-1 on Tuesday to enter the final with a 2-1 aggregate over Jamshedpur FC.
