PHOENIX (AP) -- The refrain is getting painfully familiar for the sputtering Diamondbacks: a bad outing for a starting pitcher, a frustrating loss.
Trevor Cahill couldn't make it through the fifth inning for the third time in his four starts as the Dodgers beat the D-backs 8-6 on Sunday to complete a three-game sweep.
His performance followed equally poor showings by starters Brandon McCarthy and Wade Miley in the first two games.
Cahill (0-4) was overpowering at times but walked three and gave up a three-run home run to Adrian Gonzalez in a four-run third inning.
Arizona is 4-11, and the main reason is obvious.
"The pitching, the starting pitching. Is there a question about that?" manager Kirk Gibson said. "We got five innings out of the guy today, four, that's tough. The one thing you want to go well is you want to get innings out of your starting pitchers."
Gonzalez homered for the fourth consecutive game and finished with 10 RBIs in the series. He has 27 career home runs and 87 RBIs against the Diamondbacks, most among active players.
"Man, he's smoking the ball," teammate Matt Kemp said. "He's probably the best hitter in the league right now."
Kemp and Juan Uribe also homered for the Dodgers, who scored 22 runs in the series.
"This is a good place to hit," Gonzalez said. "You go out here and take B.P. (batting practice) and the ball carries out of the ballpark. You take some of those swings and it kind of makes you feel better as a hitter."
Dan Haren (2-0) allowed three runs in 5 2/3 innings to get the victory. He scattered nine hits, striking out five and walking one.
Mark Trumbo hit a three-run home run and Eric Chavez had a solo shot for the Diamondbacks, who are off to a 4-11 start.
Dee Gordon stole a career-best four bases, the most by a Dodger in a game since Rafael Furcal did it against Arizona in 2007.
Cahill went four innings plus two batters, allowing seven runs -- six earned -- on seven hits. He struck out eight but walked five.
Asked why Cahill can be good for a stretch then fall apart, Gibson said, "I think you'd have to ask Trevor that. I don't have an answer for you."
Cahill said the walks were the big problem -- that and the one pitch to Gonzalez.
"I made a mistake, and Adrian's been swinging it good this series," Cahill said. "I kind of got away from the gameplan with him and left a pitch down and in, right in his sweet spot."
Kenley Jansen pitched a perfect ninth for Los Angeles for his fourth save and second in as many games.
The Dodgers led 8-3 before Trumbo's sixth home run of the season, off Jamey Wright with two outs in the seventh, cut it to 8-6.
Gonzalez, who also doubled, had an extra-base hit for the eighth consecutive game, one shy of the franchise record. Of Gonzalez's 14 hits this season, 10 have gone for extra bases.
Kemp's line-drive shot into the Arizona bullpen down the left-field line put the Dodgers up 1-0 in the second.
Gordon walked to start the fourth, then stole second and third. Yasiel Puig walked and Hanley Ramirez bounced one high off the plate to Cahill, beating the throw to first for an infield RBI single. Gonzalez then hit a 1-1 pitch into the right-field seats to bring in three runs and put Los Angeles ahead 5-0.
Arizona got three in its half of the third. Parra led off with a double and scored on Aaron Hill's triple to the left-center gap. Goldschmidt's groundout scored Hill, and Chavez then launched one into the right-field seats on the first pitch to cut the margin to 5-3.
Parra recorded the first right-field-to-first putout in Diamondbacks history when he threw out Haren after the pitcher appeared to have singled. It was the first throw-out at first from the right fielder in the majors in two seasons.
NOTES: The Dodgers struck out 15 times and were outhit 13-7. ... Gordon, who has nine steals, stole second in the sixth while Delgado was kicking the rubber and not paying attention. ... The Mets begin a three-game series at Chase Field on Monday night. Josh Collmenter (0-0, 2.25 ERA) comes out of the bullpen to start for the Diamondbacks against Zack Wheeler (0-2, 2.25) for for the Mets.
