Brennan Boesch had four hits and Jhonny Peralta added three as the Detroit Tigers erased a 4-1 deficit on Wednesday night and beat the Chicago Cubs 8-4.  Joe Mathers made an error on what looked to be a routine double play ground ball in the sixth, and the flood gates opened on a four run inning for the Tigers, giving them the lead for good.  Peralta had a single, double, and triple, and drove in two runs.  Boesch had three singles and a home run, and also drove in two runs.  Ramon Santiago was held without a hit, but picked up two RBI on a pair of ground outs.  The final game of a three game series is set for Thursday afternoon at Wrigley Field.