Jake Arrieta pitched four-hit ball into the eighth inning, and the Chicago Cubs beat the San Francisco Giants 2-0 on Sunday for a four-game sweep of the defending world champions. Arrieta also tripled and scored in the second as the Cubs won for the 10th time in 11 games. Chicago's first four-game sweep of San Francisco since June 1977 increased its lead for the second NL wild card to 3 1/2 games over the reeling Giants.