WASHINGTON - The San Francisco Giants left the Washington Nationals frustrated, exhausted and on the brink of elimination after they claimed an 18-inning marathon with a 2-1 win in the longest game in Major League playoff history. Brandon Belt blasted a solo home run in the 18th to snap a long 1-1 tie and the Giants seized a 2-0 lead in the best-of-five National League Division Series. The wild contest lasted six hours and 23 minutes, surpassing the previous longest post-season game of five hours and 50 minutes played by Atlanta and Houston in 2005. ...