He was aboard Butterfly Belle for the record - setting win in the fourth race at Bay Meadows .
Russell Baze becomes the winningest jockey in thoroughbred racing history , surpassing Laffit Pincay , Jr. with 9,531 career wins .
Russell Baze was aboard Butterfly Belle for the record - setting win in the fourth race at Bay Meadows .
Russell Baze becomes the winningest jockey in thoroughbred racing history , surpassing Laffit Pincay , Jr. with 9,531 career wins .