HOUSTON -- The Astros didn’t have to wait long to see what kind of night it was going to be at Minute Maid Park on Friday. After loading the bases with no outs in the first inning, three straight Houston batters struck out, though a wild pitch by D-backs starter Zac Gallen allowed George Springer to scamper home.

Houston’s offense continued its late-season swoon, going 2-for-10 with runners in scoring position, as Arizona got two home runs from Kole Calhoun to send the Astros back under .500 (25-26) with a 6-3 win in the series opener.

• Box score

“That was real frustrating, especially to go down twice looking and once swinging,” Houston manager Dusty Baker said of the first inning. “It’s real frustrating. We could have blown the game open and maybe gotten him out of the game in the first inning, and the only run we scored was on a wild pitch. Yeah, it was real frustrating for all of us.”

The Astros have lost 11 of their past 15 games, but they remain three games ahead of the Mariners for second place in the American League West. The first- and second-place teams from each division make the expanded 16-team postseason, along with two Wild Cards from each league.

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Houston's offense, which was among the most prolific in baseball for much of the season, has been in a deep freeze that has matched the team’s tailspin. The Astros are slashing .191/.249/.323 over the past 12 games, including a .143 average with runners in scoring position.

“I think we just need to string together some innings,” said Springer, who went 1-for-4 with a homer and is hitting .313 with two doubles, a triple and six homers in his past 16 games. “I think we left some guys on base a little bit, and when you don’t get it done, it is a little deflating. Again, that’s very hard to do. I just think we have to try to capitalize on our opportunities and we’ll see what happens.”

The Astros stranded a pair of runners in both the first and third, as each ended with strikeouts. They also couldn't take advantage of leadoff hits in the fourth and sixth. Houston struck out seven times, six of which were looking. Jose Altuve’s seventh-inning double was his first extra-base hit in 43 at-bats, while Yuli Gurriel and Josh Reddick are mired in deep slumps.

But Baker said this is no time to make wholesale lineup changes.

“You’ve got to go with the guys that have been there, got to go with the guys that got you here,” Baker said. “You can shake up the lineup all you want. It’s a daily game. Tomorrow could be totally different. You’ve got to go with your core guys. You have to.”

Calhoun hit a three-run homer to right field in the fourth off Astros starter Zack Greinke to put the D-backs ahead, 3-2, though Springer’s long leadoff home run to left in the fifth tied the game. After Arizona scored twice in the seventh against reliever Luis Garcia to take a two-run lead, Calhoun homered again off Blake Taylor in the eighth to make it 6-3.

“I made a bad pitch to Calhoun,” Greinke said. “It was just a bad inning.”

And a bad night for the Astros, whose lineup is sputtering with the postseason looming. When asked if it was tough creating energy on offense, All-Star third baseman Alex Bregman bristled at the idea.

“No, we’re in the big leagues,” Bregman said. “This is the highest level of baseball in the world. We’ve got to show up ready to play every single day and get after it and work hard.”