DENVER -- Nolan Arenado hit a two-run triple off Zack Greinke in the eighth inning, and the surging Colorado Rockies rallied past the Arizona Diamondbacks 4-3 on Tuesday night in the opening game of their NL West showdown.
Carlos Gonzalez homered and saved a run with a diving catch of David Peralta's line drive in the fifth to help Colorado win its sixth straight. The NL West leaders extended their advantage over third-place Arizona to two games. Second-place Los Angeles, which began the night trailing the Rockies by a half-game, played late against the New York Mets.
Peralta and Paul Goldschmidt homered for the Diamondbacks, who had won seven straight.
Arizona and Colorado, perhaps baseball's two biggest surprises this season, both entered on a roll. The Diamondbacks are a major league-best 23-9 since May 15, while the Rockies' 23-11 mark since then ranks third.
Those two teams, along with the Dodgers, have the top three records in the National League.
The series opener Tuesday was the biggest game between the clubs since the 2007 NL Championship Series that Colorado won in a sweep. The Diamondbacks took a 3-2 lead on the solo homers by Peralta and Goldschmidt, but the Rockies rallied in the eighth against Arizona's ace.
Charlie Blackmon and DJ LeMahieu singled off Greinke (8-4) with one out. Arenado, who on Sunday completed the cycle with a game-ending, three-run homer, tripled off the scoreboard in right.
Adam Ottavino (1-1) got the win despite allowing Goldschmidt's 17th homer. Greg Holland pitched the ninth for his 25th save in 26 chances.
The Rockies took a 2-0 lead with a run in the second on a throwing error and a home run by Gonzalez in the fourth. It was his fifth career homer off Greinke.
OF A.J. Pollock (groin strain) experienced quad tightness during a game for Triple-A Reno on Monday. Arizona manager Torey Lovullo said Pollock would take it easy and will be evaluated after going through "normal pregame activity" on Thursday.
Diamondbacks: RHP Taijuan Walker (5-3, 3.32 ERA) is 2-0 with a 0.82 ERA in his last two starts. He lost his only start against the Rockies this season.
Rockies: RHP Jeff Hoffman (4-0, 2.25 ERA) will make his second career start against the Diamondbacks. He allowed four earned runs in 4 2/3 innings at Arizona on Sept. 14, 2016.