A bad series turned comedically bad for the Milwaukee Brewers as the Kansas City Royals completed a three game sweep with a third straight, walk off victory Thursday night at Kaufman Stadium 4-3.   Shawn Marcum, just as Randy Wolf and Zack Greinke did before him, turned in an oustanding start.  He made just one mistake, giving up a two run homer in the 6th, one of four hits allowed in seven and two thirds innings.   Ryan Braun popped a solo home run in the 4th and Aramis Ramirez tied the game in the 7th with another.  Pinch hitter Cody Ransom singled home the go ahead run in the top of the 8th and the Brewers took a 3-2 lead into the final inning, turning the game over to closer John Axford even after he blew the save in Wednesday night's 4-3, 11 inning loss.  Axford struck out Mitch Maier to open the inning but he reached first safely when the ball rolled to the screen.   Axford walked Jarrod Dyson and then pinch hitter Brayan Pena drilled a single to left that tied the game.  What happened next looked more like the Keystone Cops.  Nori Aoki fielded the ball, threw to Edwin Maysonet as the cutoff, who for some reason, fired to Rickie Weeks at second.  Dyson kept running home and Weeks' peg to the plate was off target and the Kansas City sweep was complete.   Milwaukee (28-35) has slipped to 7 and a half games behind Cincinnati and continues interleague play this weekend in Minnesota against the AL Central's last place Twins.  Yovani Gallardo meets Francisco Liriano in the series opener at Target Field Friday night.