LOS ANGELES (AP) Ross Stripling wasn't blowing away the Arizona hitters, so when his velocity dipped the rookie gave way to the bullpen.
The Dodgers' relief corps combined with Stripling on a four-hitter and he helped himself with a go-ahead single in the second inning, leading Los Angeles to a 5-2 victory Tuesday night, the team's fourth straight.
''I heard my velocity was down. Maybe just one of those days,'' Stripling said. ''Maybe a weird day. I was happy to get through five. I'm approaching an innings limit.''
Stripling and fellow rookie Julio Urias are on unspecified innings limits.
The NL West leaders remained a season-high four games ahead of San Francisco, which beat Colorado 3-2.
''We're playing great baseball,'' right fielder Josh Reddick said. ''If we keep doing that the rest of the year we won't have to worry about them.''
Stripling (4-6) allowed two runs and three hits in five innings. The right-hander struck out five and walked none.
''I didn't want him pushing it,'' Dodgers manager Dave Roberts said. ''I saw his velocity dip down in the fourth. It was more the crispness of the pitches.''
Kenley Jansen pitched a perfect ninth to earn his 42nd save in 48 chances in his 400th career appearance. He is two from tying his career high saves set two years ago.
The Dodgers produced most of their runs on singles a night after hitting five home runs off former teammate Zack Greinke in a 10-2 victory in the series opener. They had 11 hits.
''This month and month and a half for them has been pretty amazing how they have been swinging the bat,'' Arizona starter Shelby Miller said. ''They were pretty aggressive out of the first inning.''
Miller (2-11) extended his losing streak to five games after giving up five runs and a career-high-tying 11 hits in 4 1/3 innings, his shortest start since May 1 against Colorado. The right-hander struck out two and walked none in his second start since returning from the minors on Aug. 31. He has lost 11 of 13 decisions since being acquired in a five-player trade from Atlanta last offseason.
''I'm struggling with the loss a little bit,'' Miller said, ''just kind of tired of losing.''
Stripling's first career RBI single down the first-base line with two outs in the second gave Los Angeles the lead for good at 2-1. Justin Turner tied the game with a RBI single in the bottom of the first.
Stripling, who attended Texas A&M, has known Miller for a while. Miller committed to the Aggies to play baseball, but instead signed with St. Louis after being drafted in 2009.
''That's pretty funny,'' Stripling said. ''I squeaked it right by that bag. I'm certainly no expert with the bat. I didn't hit in college or even high school, so we're learning on the run.''
The Dodgers produced three runs on five hits in the third. Yasmani Grandal's RBI groundout made it 3-1 before Reddick and Andrew Toles came up with RBI singles with two outs for a 5-1 lead.
A.J. Pollock's two-out homer in the first and Jake Lamb's sacrifice fly in the fourth accounted for Arizona's runs. The D-backs have lost four of six.
The Dodgers extended their home unbeaten streak against the D-backs to 10 straight series (9-0-1). They last lost to Arizona in Los Angeles from June 10-12, 2013. The Dodgers are 23-7 at home against the D-backs in that span.
D-backs: Recalled LHP Steve Hathaway, RHP Dominic Leone, RHP Matt Koch, OF Mitch Haniger and INF-OF Peter O'Brien from Triple-A Reno. Also reinstated LHP Andrew Chafin (left shoulder tendinitis) and C Chris Herrmann (strained right hamstring) from the DL, and added Reno manager Phil Nevin and special assistant Orlando Hudson to the coaching staff .
Dodgers: RHP Pedro Baez was recalled from Double-A Tulsa, where he didn't appear in a game after being optioned. He is 3-2 with a 3.61 ERA in 62 appearances with the big league club, having last pitched for the Dodgers on Aug. 29 at Colorado.
D-backs: LHP Robbie Ray (7-12, 4.36 ERA) is averaging 11.03 strikeouts per nine innings, fourth-best in the NL. He didn't factor in the decision in his last outing on Sept. 2 at Colorado, allowing six runs - five earned - and eight hits in 4 1/3 innings.
Dodgers: RHP Brock Stewart (0-2, 7.94) last pitched for the Dodgers on Aug. 28 against the Cubs, allowing two hits in five scoreless innings while not factoring in the 1-0 victory. He struck out a career-high eight and walked two.