ATLANTA — Evan Gattis kept up an amazing rookie season with his first grand slam, B.J. Upton and Ramiro Pena also homered, and the Atlanta Braves finished off a sweep of the woeful Minnesota Twins with a 8-3 rout on Wednesday. The Braves stretched their winning streak to six games with their second straight series sweep, making things easy for starter Paul Maholm (6-4). The left-hander held the Twins to an unearned run in 7 1-3 innings.