The Blue Square Premier Division outfit had led until the 82nd minute after Paul Rutherford had volleyed home from Millers goalkeeper Conrad Logan’s error, but Grabban scored two controversial late goals – first beating the offside trap to score before finishing from the penalty spot after a debatable handball.
Rotherham goalkeeper Logan was at fault for the Barrow opener in the 15th minute when he dropped Richie Baker’s corner before punching the ball straight to Rutherford, who volleyed into an unguarded net.
Barrow almost doubled their lead immediately as Jack Mackreth pulled the ball back for Ashley Boyes, who hit the crossbar from 12 yards.
Rotherham were the better team in the second half and deservedly equalised with less than 10 minutes to go as Grabban beat the offside trap, despite Barrow’s appeals, to score from 10 yards.
Grabban then scored the winner from the penalty spot following a controversial handball decision as the ball struck Mackreth just inside the area following Gareth Evans’ cross.