Cody Ross finished 4-for-5 with a pair of doubles, a game-winning home run, three RBI and two runs scored, helping Arizona take a 7-6 decision over Boston in the opener of a three-game interleague set from Fenway Park.
Paul Goldschmidt clubbed a two-run shot, while Martin Prado added two doubles, scored twice and drove in a run for the Diamondbacks, who have won two of three.
Randall Delgado (4-3) labored through six innings, allowing six hits and six runs -- four earned -- but fanned seven and walked just one for the victory.
Stephen Drew homered to fuel a three-RBI performance, and David Ortiz hit a two-run shot for the Red Sox, who failed to maintain momentum after sweeping Seattle in the series prior.
The BoSox maintained their one-game lead in the AL East, as the Rays dropped their interleague series opener, 4-1, to San Francisco.
Pedro Beato (1-1) served up Ross' deciding blast. Starter Jon Lester lasted only 4 1/3 frames, tagged for 11 hits and six runs with six strikeouts.
"We started to put it together," Red Sox manager John Farrell said. "Things started to build, a little momentum, similar to the feeling that we've had the last couple of nights. But, unfortunately, it didn't happen here tonight."
Ross kicked off the seventh by greeting Beato with a shot that barely cleared the Green Monster to give Arizona a 7-6 advantage, then Boston stranded a runner on third in the home portion. Joe Thatcher, making his first appearance in an Arizona uniform after being traded from San Diego, retired Ortiz on a foul pop.
"Obviously, I want to come in here and perform and play well. Anytime you play against one of your old teams, you want to do that," Ross said, "But I have no hard feelings toward anybody in this organization."
Drew singled to begin the ninth and Jacoby Ellsbury pushed a ball through the right side with one out. However, Shane Victorino flied to left and Dustin Pedroia bounced out to end the game and earn Brad Ziegler his sixth save.
Lester ran into trouble early, as Aaron Hill's one-out single in the first was followed by a two-run blast from Goldschmidt.
Ellsbury began the home half with a triple, then Ortiz evened the game with a two-run homer to dead center. Boston extended its lead to 4-2 in the following frame on a pair of sacrifice flies from Drew and Brock Holt.
Ross singled home Prado in the third to draw Arizona within a run, and the visitors moved ahead in the fifth.
Hill led off with a two-bagger, Prado doubled him in with one down and Ross added an RBI double for a 5-4 contest. Jason Kubel contributed a base hit to plate Ross, and Lester was pulled for Matt Thornton. Though Wil Nieves reached on an infield single, Didi Gregorius struck out to keep it a two-run margin.
Mike Napoli singled to start the bottom of the sixth. After Jarrod Saltalamacchia flied out to right-center just in front of the bullpen, Drew managed to deposit a Delgado pitch over the wall in virtually the same spot to forge a 6-6 deadlock.
Ross hit .267 with 22 homers, 34 doubles and 81 RBI in 130 games for the Red Sox last season, but left to test the free-agency waters after the club informed him they wouldn't re-sign him to a long-term deal ... The clubs hadn't met since June 15-17, 2010, when the Red Sox recorded a three-game sweep ... Friday's victory snapped Arizona's five-game losing streak to Boston dating back to June 23, 2008 ... The Sox still lead the all-time series 7-6 ... Lester's outing was his shortest of the season, one-third of an inning shorter than a 4 2/3 inning performance in an 8-3 loss at Tampa Bay on June 11.