Watch: DJ LeMahieu HR Rallies NL-West Leading Rockies to Walk-Off Win Against D-Backs

The Rockies have never held sole possession of first place this late in the season since 1995.

DENVER — DJ LeMahieu hit a two-run homer off Yoshihisa Hirano in the ninth inning, and the NL West-leading Colorado Rockies rallied to beat the Arizona Diamondbacks 5-4 on Wednesday night.

LeMahieu hit a fastball over the fence in right as the Rockies kept their 1½-game advantage over Los Angeles intact after the Dodgers beat Cincinnati earlier in the day. The Diamondbacks fell 3½ games behind in the division race. This is the latest in the season the Rockies have been alone in first place since 1995.

Trying for a save on consecutive nights, Hirano (4-3) allowed a single by Gerardo Parra off the glove of first baseman Paul Goldschmidt to begin the ninth. Charlie Blackmon bunted Goldschmidt over to second and LeMahieu followed with his first career walk-off homer. He was doused with water after crossing home plate as fans chanted “DJ, DJ, DJ!”

Wade Davis (3-6) picked up the win by pitching a perfect ninth, including two strikeouts.

Nolan Arenado had a big night for the Rockies with two doubles and a solo homer.

LeMahieu’s blast spoiled a solid outing by Diamondbacks starter Patrick Corbin, who allowed a season-high 10 hits, but navigated his way through trouble. He went 6 1/3 innings and allowed three runs.

The left-hander’s most crucial pitch was a slider to strike out LeMahieu with the bases loaded in the fourth.

Arizona’s bullpen bent a little in the eighth, issuing two walks, only to have reliever Archie Bradley enter with two outs and get pinch-hitter Carlos Gonzalez to roll out.

Eduardo Escobar’s homer in the third inning was his 21st of the season and sixth with the Diamondbacks since being acquired from the Minnesota Twins on July 27. Goldschmidt finished 2 for 4 with a double and extended his streak of reaching base to 48 straight road games. Alex Avila added a solo homer.

Since 2015, the Diamondbacks are now 17-6 against Colorado during games played in September or later — including their win in the NL wild-card contest last October.

Rockies starter Jon Gray labored on a night he didn’t have his best stuff. He was knocked out after four innings, allowing four runs.