DENVER (AP) - Nolan Arenado hit a two-run triple 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.