CHICAGO -- Jake Arrieta has been pitching well for a while now. This time, he also contributed with his bat.
Arrieta tripled and scored in the second, and then pitched four-hit ball into the eighth inning as the Chicago Cubs beat the San Francisco Giants 2-0 on Sunday for a four-game sweep of the defending world champions.
Rookies Kris Bryant and Addison Russell each drove in a run, helping the Cubs to their 10th win 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.
"Because of the division we're in, the two teams ahead of us, we know they're not slowing down and we don't intend to either," Arrieta said. "What we have to do now is just continue to make it difficult for the guys ahead of us and continue to show we're going to put pressure on and not let up."
Arrieta (13-6) struck out six and walked two in 7 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.
"Win the first three with a chance to sweep, I was in the mindset of coming out to dominate today and put us in the situation where we only needed one or two (runs)," Arrieta said.
Right after Chicago's fourth straight win, Wrigley Field was evacuated and Police with dogs searched the ballpark. It was reopened about an hour later.
Chicago Police spokesman Thomas Sweeney said the department received a telephone threat that prompted officers to investigate. He declined to provide further details about the nature of the threat.
"We're just playing well," Cubs manager Joe Maddon said. "We've hit the ball better overall in the series, we're catching the ball and the starters have done a really nice job for the most part. The bullpen, we still have to get that on firm ground."
San Francisco loaded the bases with no outs in the ninth 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 - the Cubs (62-48) moved a season-high 14 games over .500 - Blanco had a few words with home plate umpire Jim Reynolds about the final pitch.
"I didn't have my good fastball today, so I came in with what I had," Rondon said.
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.
"We didn't really make a lot of errors to beat ourselves," Giants catcher Buster Posey said. "They just outplayed us these four games."
Kyle Schwarber walked and scored on Bryant's two-out single in the first. Arrieta's second career triple set up Russell's sacrifice fly.
"Jake was outstanding," Maddon said. "Even his lumbering triple was really interesting to watch."
Giants: LF Nori Aoki left in the third inning after getting drilled in the helmet by a 92 mph fastball from Arrieta. Aoki was tended to by a Giants trainer and walked off the field under his own power. He is expected to be evaluated on Monday. ... RHP Tim Hudson (right shoulder strain) is eligible to be activated from the disabled list on Tuesday.
Giants: After an off day on Monday, Madison Bumgarner (12-6) is scheduled to start Tuesday against the Astros. Bumgarner is 3-1 in his career against the Astros with a 2.93 ERA.
Cubs: Dan Haren is scheduled to make his second start for the Cubs against the Brewers on Tuesday. He allowed four runs in five innings against Pittsburgh on Wednesday.
"Starlin will be fine," Rizzo said. "I know obviously this is a low point for him. He's a great teammate. He's a great person. He's a good leader, too. He doesn't get down. He doesn't get too high during the highs or too low during the lows."