SAN FRANCISCO — Madison Bumgarner pitched two-hit ball over seven innings, Brandon Crawford drove in the go-ahead run with a double-play grounder after a key bunt stopped just fair along the third-base line and the San Francisco Giants beat the Detroit Tigers 2-0 on Thursday night to take a 2-0 World Series lead. Bumgarner, who lost both his starts in the NL playoffs, struck out eight and walked two, and Santiago Casilla and Sergio Romo finished with perfect relief. Hunter Pence led off the seventh with a single off Doug Fister, and reliever Drew Smyly walked Brandon Belt.