Orlando Arcia singled in the go-ahead run in the top of the 12th inning as the Brewers beat the Padres 2-1 on Opening Day at Petco Park.  Christian Yelich drove in the other run and Lorenzo Cain went 3-for-5 in their Brewers debut.  Starter Chase Anderson allowed just one hit over six scoreless innings.  Jeremy Jeffress grabbed the win and Jacob Barnes earned the save. The Brewers continue their three-game, season-opening series tonight in San Diego against the Padres.  Jhoulys Chacin (Jo-lease  sha-Seen) will make his Milwaukee debut.  The Friars will counter with rookie left-hander Joey Lucchesi.