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.
Arrieta (13-6) struck out six and walked two in seven 2-3 innings. The right-hander is 7-1 with a 1.23 ERA in his last 10 starts dating to a four-hit shutout at Minnesota on June 21.
Justin Grimm got the final out of the eighth, and Hector Rondon worked out of a jam in the ninth while recording his 19th save in 22 chances.
San Francisco loaded the bases with no outs on two hits and a hit batter. But Rondon responded with three straight strikeouts, including Gregor Blanco on a called third strike to end the game.
While the crowd of 39,939 cheered wildly, Blanco had a few words with home plate umpire Jim Reynolds about the final pitch.
Kris Bryant singled in a run in the first for the Cubs (62-48), who moved a season-high 14 games over .500.
Giants right-hander Jake Peavy (2-5) allowed four hits, struck out six and walked two in five innings. He was the only San Francisco starter to record an out in the fifth in the series.
The Giants concluded a 10-game road trip with a 3-7 record.
Peavy needed 12 pitches to strike out leadoff hitter Dexter Fowler in the first, and it was a sign of things to come. He finished with 101 pitches, compared to 117 for Arrieta.
Kyle Schwarber walked and scored on Bryant's two-out single to right. Arrieta's second career triple set up Addison Russell's sacrifice fly.