Miguel Montero had a career-high two triples and scored once for the Diamondbacks, who recorded their first series win over Los Angeles since August 14-16, 2009. Sam Demel (2-1) received the win despite giving up two runs in one inning of relief.
Juan Gutierrez earned his 14th save of the season.
Chad Billingsley was in line for the win after tying a career-high with 13 strikeouts in seven strong innings for the Dodgers, who have lost eight of 11. Billingsley, who had lost his last three starts, allowed just one run on four hits and a walk.
After Billingsley departed, the Dodgers bullpen ran into some trouble in the eighth.
With one out, George Sherrill walked Stephen Drew before surrendering Abreu's home run, cutting Arizona's deficit to 4-3. After Sherrill yielded a single to Kelly Johnson, Jonathan Broxton (5-6) came in and served up Young's go-ahead two-run blast to left.
Gutierrez came in and pitched around a two-out single in the ninth to seal the win for Arizona.
Both teams lit the scoreboard in the fifth, when the Dodgers scored twice and the Diamondbacks answered with one run.
Montero led off the home half with a triple and was able to score two batters later on Cole Gillespie's sacrifice fly.
The Dodgers looked to increase their lead in the sixth with runners on the corners and one out, but Rafael Furcal grounded into a double play.
Montero began the seventh with another triple, but was thrown out at home trying to score on a Gillespie ground ball. Gerardo Parra struck out to end the threat.
Barajas added a two-run homer for Los Angeles in the eighth.
The Diamondbacks have won five of six overall...Barajas hit his 17th homer of the season...Montero hit his first two triples of the season...The Dodgers still lead the season series, 11-4...Abreu hit his third career homer and first since 2007 while with the Dodgers...Joe Saunders started for Arizona and gave up two runs in five innings...Broxton recorded his seventh blown save of the season.