OAKLAND -- Jake Arrieta threw eight scoreless innings and Ben Zobrist chipped in a two-run single as the Cubs beat the A's, 4-0, on Saturday, while Oakland starter Sonny Gray left the game due to injury after five innings.
Chicago has won six straight games and 16 of its past 22. Arrieta was superb, holding Oakland to three hits in his 13th win and departing to strong applause from a hearty Cubs contingent at the Coliseum. Only two A's baserunners reached second base against the righty, who has the league's fifth-best ERA (2.59) among qualified starters.
"We're having a nice stretch here," Arrieta said. "It's nice to have six in a row, but tomorrow it doesn't matter."
Arrieta retired 10 of the last 11 batters he faced. Saturday marked the second straight start Arrieta pitched into at least the eighth inning and the third time in four starts he allowed two runs or fewer. It was a welcome sight for the righty after he went 0-3 with a 4.88 ERA in July.
Gray entered amid his own July struggles, but he was better Saturday until a sore right extensor muscle in his forearm forced his sudden departure. He held Chicago to two runs on five hits over five innings, including Zobrist's two-out, two-run single in the third. Gray was replaced by Liam Hendriks, who gave up two runs on RBIs by Addison Russell and Jorge Soler to make it 4-0.

Gray said he wanted to return for the sixth, but he realized it wasn't the best decision.
"We decided to shut it down there instead of risking anything else," Gray said. "I lobbied to go back out there, but it just seemed like it obviously wasn't going to happen."
The A's have now been shut out seven times, and Gray has been the loser in three of them. He still owns the league's highest ERA (5.74) among qualified pitchers and lost his career-high 11th game.
Both teams donned throwback-style uniforms on a day in which Oakland honored its 1981 team. The Cubs now have a league-best record of 68-41, while the A's lost for the seventh time in their past eight games, falling a season-high 14 games below .500.
MOMENTS THAT MATTERED
Key two-out hit: Zobrist stroked a solid single into center field to drive in Willson Contreras and Dexter Fowler, who led off the third inning with singles. A strikeout and groundout later, Gray had a chance to get out of the frame without damage. Zobrist, a former A's teammate, dashed that hope.

"It's been an up-and-down season," Zobrist said. "You don't want that. I'm back to feeling healthier, feeling strong and getting back into the rhythm of the game." More >
Gray's day ends abruptly: Gray wasn't perfect, allowing five hits through the first three innings, but he didn't surrender a hit over his last two frames and retired the final seven batters he faced. So it came as a surprise when Hendriks trotted in from the bullpen to begin the sixth inning, ending Gray's day after just 72 pitches and cutting short what appeared to be a bounce-back start for the righty. The team later announced Gray's injury.
"He was throwing the ball pretty good today," A's manager Bob Melvin said. "The one inning where he gives up two runs is two bloop hits … I thought he got out of a jam before that. It looked like he was throwing the ball really well." More >
Back on the road again: Following three winless outings on the road, Arrieta got back on track with his masterful effort. He's now 20-2 over his past 23 road starts.
"That was nice," Cubs manager Joe Maddon said. "He kept his command. He had two or three key pitches -- the 3-0, 3-1 grounder where we didn't get the double play and the 3-0 fly ball [to Khris Davis in the fourth]. Those were big pitches for him."
A's flash the leather: Gray found himself in trouble in the second, allowing back-to-back singles to begin the inning, but two strong defensive plays from young infielders kept Chicago off the scoreboard. Max Muncy made a diving stop at second base on a Jason Heyward grounder for the first out, and third baseman Ryon Healy snared a Jorge Soler chopper and fired home to throw out Zobrist on the next at-bat, keeping the game scoreless.

QUOTABLE
"I like color. Swing back to the '80s. They actually look good and they're very comfortable." -- Maddon, on the 1981 throwback road jersey
AFTER FURTHER REVIEW
The Cubs challenged a call at first base in the seventh inning after the A's Danny Valencia initially beat out a ground ball to third baseman Kris Bryant. After review, it was determined that first baseman Anthony Rizzo kept his foot on the bag, and the call was overturned.

WHAT'S NEXT
Cubs: Right-hander Kyle Hendricks makes the start in Sunday's 3:05 p.m. CT series finale. He's coming off his second career shutout, which he accomplished with a season-high 123 pitches. He's never faced the A's, and he is 2-6 with a 3.75 ERA on the road.
Athletics:Sean Manaea (3-6, 4.68 ERA) starts at 1:05 p.m. PT Sunday at the Coliseum. The rookie is 1-2 with a 3.14 ERA in seven starts since coming off the disabled list on June 29, but he took the loss Tuesday in his last start against the Angels, giving up four runs in 5 2/3 innings.
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