Rookie Williams Perez threw six innings and the Atlanta Braves’ bullpen did the rest as they recorded a rare shutout in beating the Washington Nationals 2-0 on Wednesday night. A.J. Pierzynski had an RBI single in the first inning one night after hitting two home runs, and Michael Bourn singled home the Braves’ other run in the second. Rookie Arodys Vizcaino earned his 10th save — and second in two nights — with a perfect ninth.