HOUSTON (AP) When Chris Carter stepped up to the plate with the game tied in the 10th inning, Houston manager Bo Porter wasn't thinking about his sub-.200 batting average and the fact that he had struck out twice Thursday night.
The only thing on Porter's mind was Carter's penchant for changing a game with one swing.
''He has the ability that when he steps into the batter's box he's in scoring position,'' Porter said.
Carter homered leading off the bottom of the 10th inning to give the Astros a 5-4 victory over the Arizona Diamondbacks.
Carter, who homered twice on Wednesday, hit his 13th homer of the season into the Crawford Boxes in left field off J.J. Putz (1-1).
''We found out again tonight why we keep running him out there,'' Porter said of Carter, who has had an up-and-down year and is hitting just .199.
There was no doubt about the second game-ending homer of his career.
''As soon as I hit it I knew it was going to be out and started celebrating almost in the box,'' he said.
Putz lamented the pitch he threw to Carter.
''He put a pretty good swing on it,'' Putz said. ''There's nothing else to say. I just didn't make the right pitch, I guess.''
Miguel Montero tied it at 4-4 in the ninth with a home run to left field on the first pitch from closer Chad Qualls.
It was a game that last year's Houston team would have almost certainly lost. But players and staff alike agree that things are finally starting to turn around for this team that has lost 100-plus games in three straight seasons.
''It's been real exciting compared to last year, it's like night and day,'' Carter said. ''Last year we lost a bunch of games and guys were down on themselves and it just kind of seemed like there was a really bad vibe and this year everyone's excited, jumping around, having fun.''
Carlos Corporan had a two-run home run and Jon Singleton homered and drove in two runs for the Astros (31-37), who have won six of their last eight games.
Tony Sipp (1-0) struck out one in a scoreless 10th for the win.
Singleton drove in a run with a sacrifice fly in the first inning and broke a 1-all tie with his solo shot to right field in the third. Corporan extended Houston's lead to 4-1 with his home run to left field in the fourth.
Chris Owings hit a solo homer to get Arizona within 4-3 in the seventh inning.
Houston second baseman Jose Altuve was hit on the right hand by a pitch in the seventh inning. X-rays were negative and he is listed as day-to-day.
David Peralta singled for Arizona's first hit with one out in the third inning. Ender Inciarte reached on an error by Altuve that left Peralta at third and he scored on a sacrifice fly by Didi Gregorius to tie it at 1-1.
Enciarte was shaken up in that inning when he took a knee to the head from Jonathan Villar while stealing second base. He remained in the game but was replaced by Cody Ross in the bottom of the sixth as a precaution.
Springer had two nifty defensive plays. The first one came when he sprinted from right field to center and dived to make the catch on a ball hit by Owings for the first out of the fifth.
Springer made another excellent diving catch on a fly ball by Martin Prado to start a double play to end the eighth. Paul Goldschimdt was on second and had almost reached home when Springer caught it, allowing Villar to step on second base to end the inning.
The Astros celebrated ''Drake Day'' on Thursday with the Grammy Award-winning rapper attending the game and talking to students from the Astros Urban Youth Academy before the game. Each player came up to bat to music by the rapper and Singleton chose the tune ''All Me.''
Seconds after the music trailed off with one out in the third inning, Singleton caught all of a 90 mph fastball from Wade Miley and launched a towering homer into the second deck in right field to give Houston a 2-1 lead.
NOTES: The Diamondbacks acquired INF/C Jordan Pacheco from the Rockies and designated INF/OF Nick Evans for assignment before the game. ... Arizona manager Kirk Gibson said he doesn't expect OF Mark Trumbo, who has been out since April 22 with a stress fracture in his left foot, to return to full baseball activities for at least three more weeks.