Gerardo Parra went 2-for-3 and knocked in 2, game series.
Paul Goldschmidt and Ryan Roberts each had two hits and an RBI for the D- Backs, who have won five of six to stay 8 1/2 games ahead of the Giants atop the NL West standings.
Joe Saunders (11-12) was effective through seven frames, allowing just four hits and two runs to earn the win.
"My game plan was to throw strikes and not walk anyone," Saunders said. "I was able to mix my pitches. I was able to get ahead of guys and make them hit my pitch."
Ted Lilly (9-14) was handed a career-worst 14th loss after surrendering three runs on three hits and three walks in 5 1/3 innings of work.
"Ted pitched good. It was one of those games you question yourself of taking him out," Dodgers manager Don Mattingly said. "It didn't work out tonight."
Matt Kemp's home run in the first inning, his 33rd of the season, was the lone offense for Los Angeles until Jerry Sands singled in a run in the seventh.
Lilly kept the visitors off the board over the first five frames, but Willie Bloomquist led off the sixth with a single and raced around to score on Aaron Hill's double.
Guerrier was pulled without recording an out, and Parra greeted Scott Elbert with a two-run single to left, pushing the margin to 5-1.
Parra doubled in a pair in the eighth, and D-Backs closer J.J. Putz stranded the bases loaded in the ninth to secure his 39th save.
D-Backs catcher Miguel Montero went 0-for-3 to snap an 18-game hitting streak...Sands had half of the Dodgers' six hits.