Ketel Marte had four hits, Zac Gallen earned his 16th win and the Arizona Diamondbacks won their fourth straight game by beating the San Francisco Giants 8-4 on Tuesday night. The Diamondbacks remain a half-game in front of the Chicago Cubs for the second of three National League wild-card berths. The Giants, who have dropped four of five, fell three games behind the Cubs for the final playoff spot.