KANSAS CITY, Mo. — Back in the playoffs after 29 years, the Kansas City Royals ran wild and outlasted the Oakland Athletics in a thrilling opener to baseball's postseason.Salvador Perez singled home the winning run with two outs in the 12th inning, capping two late comebacks that gave Kansas City a 9-8 victory over Oakland on Tuesday night in the AL wild-card game.Quite a start to October baseball, even if this one appeared to be over with plenty of time to spare in September.