DENVER -- The D-backs were two outs away from pulling to within 1 1/2 games of the first-place Rockies in the National League West on Wednesday night, with a chance to cut it to one-half game Thursday.
They had gotten some offense off Colorado starter Jon Gray, and their bullpen-by-matchup strategy was working for the second game in a row.
And then, it all came crashing down as DJ LeMahieu hit a Yoshihisa Hirano fastball over the scoreboard in right field to give the Rockies a 5-4 walk-off win at Coors Field.
The gut-punching losses are getting harder to keep track of for the D-backs, who lost three such games to the Dodgers in Los Angeles at the beginning of the month and another three to the Braves at home before coming here.
In all six of those games -- and on Wednesday -- Arizona had a lead in the seventh inning or later, only to watch it evaporate.

"It's pretty painful," D-backs manager Torey Lovullo said. "It's obvious. I know we play this game for 27 outs, and we can't seem to close the deal when we need to. These are important games, we know that, and we're doing a lot of things right, with the exception of finishing the games off."
The D-backs did do a lot right.
Eduardo Escobar hit a two-run homer in the third and Alex Avila added a solo shot in the fourth as the D-backs chased Gray from the game after four innings.

Meanwhile, Patrick Corbin pitched his way out of trouble, allowing 10 hits but only three runs over 6 1/3 innings.
Right-hander Brad Ziegler got out of a jam in the seventh, and Archie Bradley pitched out of another in the eighth.
Then came the ninth.
One day after he picked up his first Major League save, Hirano allowed pinch-hitter Gerardo Parra to reach on an infield single, and Charlie Blackmon sacrificed Parra to second. That brought up LeMahieu, who fouled off a fastball and took a split-finger pitch for a ball before hitting a high fastball to right for a game-ending homer.
Hirano said through an interpreter that he was trying to throw the pitch outside and "just was trying to get low, but it got away, and it was kind of up where he could hit it."
While the D-backs' bullpen will shoulder the loss, it was again the offense that left the relievers with little margin for error.

After Avila's homer in the fourth, the D-backs made 17 consecutive outs. A trio of Rockies relievers came on to toss five perfect innings, marking the first time that happened in Colorado's history.
"I think that's been happening a lot lately, where we have a chance to break the game open and we don't," Lovullo said. "Hitting is hard, especially with men in scoring position. We're trying. We're trying to do our best to break it open. It's when you're fighting for the same turf and you haven't got it done. Tacking on and extending leads, those are things we're talking about, we're actively engaged with the players, and they understand how important it is. It's not for a lack of effort. It's not one of those things that seems to be working right now."
MOMENT THAT MATTERED
Tough play: Parra's single to lead off the ninth was hit sharply, one-hopping first baseman Paul Goldschmidt and hitting off his glove for an infield hit. The ball left the bat at 98 mph, and it had the three-time NL Gold Glove Award winner replaying the moment in his mind after the game ended.
"Obviously, since the game ended, I'm thinking about, 'Could I have done anything different?'" Goldschmidt said. "It's mostly just a reaction. I got my glove on it, but wasn't able to come up with it. It's just one of those plays. Of course, I would love to make that play. It's unfortunate that it potentially cost us that game. I just try to make every play and wasn't able come up with that one."
SOUND SMART
The D-backs are 18-28 in one-run games this year. And while they have been losing leads in the second half of the season, the Rockies have been coming back. In Colorado's 29 wins since the All-Star break, it has trailed at one point in all but seven.
HE SAID IT
"Every inning, we're going in and trying to score and get runners on. We weren't able to do a good enough job tonight. We did a good job off Gray, getting those hits and getting some baserunners. Their bullpen came in and did a good job. We were trying to tack on a run or two or however many we could get. We just weren't able to do it tonight." Goldschmidt, on the team's offensive struggles
UP NEXT
The D-backs look to split the four-game series with the Rockies on Thursday afternoon at 12:10 p.m. MST at Coors Field, with right-hander Clay Buchholz (7-2, 2.01 ERA) set to take the mound. This will be the first career start at Coors Field for Buchholz, who is 6-1 with a 1.54 ERA over his last 11 starts. The Rockies will counter with left-hander Kyle Freeland (14-7, 2.91). The game can be watched exclusively on MLB Live on Facebook.