PHOENIX -- Nolan Arenado's tie-breaking three-run home run in the eighth inning powered the Colorado Rockies to a 5-4 win over the Arizona Diamondbacks on Monday night.
The Rockies took the first game of a key four-game series between the National League wild-card leader, Arizona, and second-place Colorado. The Rockies moved four games behind the Diamondbacks and 3 1/2 ahead of St. Louis for the second wild card slot.
Arenado drove in four runs with a double and his 33rd home run of the season, and the Rockies won their seventh straight road game and fifth overall.
Left-hander Tyler Anderson, activated from the 60-day disabled list on Sunday, pitched four scoreless innings in relief for the victory. Anderson (4-5) allowed a hit with four strikeouts.
The Rockies' winning rally started with two outs in the eighth. D.J. LeMahieu tripled over the top of an extreme defensive shift toward right field and Carlos Gonzalez walked against Diamondbacks reliever Jake Barrett (1-1).
Arenado's home run followed, giving him a major-league leading 123 runs batted in on the season. He was seen exchanging words with a vocal fan sitting near the visiting dugout after crossing home plate.
The Diamondbacks came back with two runs in the bottom of the eighth off Rockies relievers Jake McGee and Pat Neshek. Paul Goldschmidt's ground out drove in Chris Iannetta, and hot-hitting J.D. Martinez singled in A.J. Pollock to cut Colorado's lead to 5-4.
Martinez, on the same day he was named NL Player of the Week for last week when he batted .429 with seven home runs, went 3-for-4 and scored twice.
Mike Dunn got pinch hitter Daniel Descalso to fly out to deep center to end the eighth, and Greg Holland pitched a scoreless ninth for his NL-leading 40th save.
Holland stranded runners at second and third, inducing a Pollock ground out to end the game.
Diamondbacks starter Zack Greinke allowed two runs on five hits with six strikeouts over seven innings.
Greinke, with his fifth-inning strikeout of Anderson, reached 200 strikeouts on the season for the sixth time in his career, all six times since 2009.
The bat that Martinez used to hit four home runs at Dodger Stadium on Sept. 4 was packed up at Chase Field and sent to the National Baseball Hall of Fame in New York on Monday.
Rockies: RHP Jon Gray (7-4) has a 2.55 earned run average over his last seven starts, but he's 1-2 with 5.40 career ERA against Tuesday's foe, Arizona.
Diamondbacks: RHP Taijuan Walker (9-7) faces Colorado with the Diamondbacks having won in each of his past four starts.