Arietta won his 19th consecutive decision Friday night, limiting the Giants to four hits and one walk while striking out eight in seven innings as the Chicago Cubs won 8-1 to snap San Francisco's eight-game winning streak. Jake Peavy (1-5) allowed five runs on seven hits and two walks over 1 2/3 innings. ''(Peavy) was just missing his spots tonight, his pitch count I'm sure caught up with him,'' Giants manager Bruce Bochy said.