LOS ANGELES — Zack Greinke heard it from the fans first. Boos rang out in his initial at-bat against his old team. Then the Dodgers let him have it, blasting their former ace for a career-worst five home runs in his first road start against them.

The crowd of 41,820 reacted loudly again when Greinke walked off with his head down after getting yanked in Arizona’s 10-2 loss Monday night.

“I feel I should be getting outs better than I am,” he said. “I am not consistent right now, a couple of bad outings.”

Greinke (12-5) imploded in his return to Dodger Stadium for the first time since spurning the team as a free agent last December.

He signed a $206.5 million, six-year deal in the desert after winning 51 games and compiling a 2.30 ERA from 2013-15 as part of a 1-2 punch with ace Clayton Kershaw in Los Angeles.

Greinke gave up eight runs and nine hits in 4 2/3 innings and struck out six. Four of the five homers came in the fifth inning. He hadn’t allowed a homer in his last three starts.

“I don’t know what it is at the moment,” he said. “But I am going to try to find out what is going wrong and try and do better.”

Arizona slugger Paul Goldschmidt chalked up Greinke’s poor outing to “one of those nights.”

“Zack is a good pitcher and we have confidence in him,” he said. “I have got to give those guys some credit, they are really good and took some really good swings.”

Last season, Greinke led the majors with a 1.66 ERA, won a career-high 19 games and was an NL All-Star while helping the Dodgers win a third straight division title. Now, they are in pursuit of a fourth, while the D-backs have failed to contend this season and are mired in next-to-last place.

“Usually he is able to get out of those innings and stop the bleeding but he just wasn’t able to do it,” Arizona manager Chip Hale said. “The location wasn’t there and they did a good job of exploiting it.”

Jake Lamb’s RBI single and Chris Owings’ RBI double accounted for Arizona’s runs.

Kenta Maeda (14-8) allowed one run and three hits in 6 1/3 innings, struck out eight and walked one to tie Kazuhisa Ishii and Hyun-Jin Ryu for the second-most wins by a Los Angeles rookie, trailing only Rick Sutcliffe’s 17 in 1979.

The Dodgers increased their lead in the NL West to a season-high four games over San Francisco, which lost 6-0 at Colorado. They have won four of five.

Adrian Gonzalez broke open a scoreless game with a two-run shot in the fourth, a preview of what was to come.

After Howie Kendrick grounded out to open the fifth, Greinke gave up five consecutive hits. Joc Pederson hit a solo shot, his sixth homer in as many games against Arizona.

Two hitters later, Corey Seager slammed a three-run homer into the pavilion in left field. Justin Turner followed with a solo shot in nearly the same location as fans directed a derogatory chant at Greinke.

With two outs, Yasmani Grandal homered to right field, making it 8-0.

GREINKE AT THE RAVINE

Until Monday, Greinke had been dominant at Chavez Ravine, winning his previous eight starts and compiling a 1.09 ERA dating to July 4, 2015. He was one of five pitchers to win eight-plus consecutive starts there, the longest active streak in the majors at a single ballpark. The right-hander had limited the opposition to two or fewer earned runs in 14 straight starts at the stadium. Greinke had beaten the Dodgers once this season, 3-2 on June 13 at Arizona.

TRAINER’S ROOM

D-backs: LHP Andrew Chafin (shoulder, groin) will be activated Tuesday after pitching a scoreless inning last weekend for Triple-A Reno.

Dodgers: RHP Brandon McCarthy (right hip stiffness) was to make his first rehab start Monday for Class-A Rancho Cucamonga. He last pitched on Aug. 13. … LHP Scott Kazmir (neck inflammation) will make a rehab start Wednesday for Triple-A Oklahoma City. … LHP Alex Wood (posterior elbow impingement) will throw a bullpen session in a few days, followed by a simulated game. … RHP Pedro Baez will rejoin the team on Tuesday now that Double-A Tulsa’s season has ended.

UP NEXT

D-backs: RHP Shelby Miller (2-10, 6.81 ERA) makes his second start in the majors since July 6. He allowed two runs in six innings of a loss at San Francisco on Aug. 31. He last faced the Dodgers on July 20, 2014, when he tossed a scoreless inning of relief as a member of the Cardinals.

Dodgers: Ross Stripling (3-6, 4.15) is 2-4 with a 4.84 ERA in nine games (seven starts) at home. The right-hander has struck out 30 and walked 13. He has a 3.72 ERA in two games (one start) against Arizona this season, limiting the opposition to a .229 average.