PHOENIX -- Once again, Justin Upton was hit.
Once again, Miguel Montero had his back.
And once again, the D-backs won.
Montero's second three-run homer in as many games, backed by solid pitching and stellar defense, powered the D-backs to their ninth straight win Wednesday night, a 4-2 decision over the Rockies in front of 23,062 at Chase Field.
"Miggy responds," said D-backs manager Kirk Gibson. "I guess we should like when people get hit."
The D-backs remained six games ahead of the Giants in the National League West as a three-game weekend showdown in San Francisco looms.
"It will be a rabid environment," Gibson said. "It's never easy, but we're ready."
Montero's first-inning home run -- a rocket to right field off right-hander Esmil Rogers -- gave Josh Collmenter all the offense he needed to earn a ninth straight victory by a D-backs starting pitcher.
His 14th blast came after Upton was drilled in the left shoulder for the 16th time this season, not unlike Montero's run-scoring single to follow Upton's first hit-by-pitch of the series on Monday.
"He's swinging the bat well," Gibson said of Montero, who tied a career-high with a 10-game hitting streak. "I know that people think about pitching around [Upton], so somebody has to respond, and he's been on fire."
A strong defensive effort -- "They played great," said Collmenter -- gave the right-hander all the comfort he could ask for. He threw six innings, allowed two runs on five hits, struck out three and walked none for victory No. 9.
It was the sixth time he hasn't allowed a walk this season, and each time has resulted in a "W."
"When you're not walking anybody and you're making big plays like that consistently, it just helps you hold them down," Gibson said.
Collmenter's defense picked him up from the get-go, when Dexter Fowler attempted to score from third base on a Carlos Gonzalez fly ball to left field in the first inning.
Gerardo Parra nailed the speedy Fowler with a one-hopper to Montero at home plate, who applied an outstretched tag to end the inning and solidify Parra's ninth outfield assist of the season.
"Parra's play in the first inning really bailed me out," Collmenter said. "Then [Montero]'s three-run home run gets all the momentum on our side, and from there, playing with a lead, you don't want to give it up."
An inning later, as Eliezer Alfonzo delivered a two-out single to plate Seth Smith, Montero cut Alfonzo down trying to advance to second to escape the inning.
But those two throws were no match on the highlight reel for Aaron Hill's fourth-inning snag of a Todd Helton ground ball.
With Gonzalez on second after a leadoff double, Helton unleashed a one-out screamer up the middle. Hill laid out to his right, securing a tough high hop, and flipped to first for the out. Collmenter retired the next batter, Gonzalez was stranded at third and the Rockies didn't score another run.
Hill recorded his third multi-hit game in his past four starts with a two-out double in the sixth before Rockies manager Jim Tracy elected to intentionally walk Parra to face the pitcher's spot.
Gibson opted to send Sean Burroughs to the plate despite Collmenter having thrown just 85 pitches, and the response was a sharp single up the middle, off Rogers' glove, that brought home Hill with an insurance run.
"You kind of take it personal a bit when you get somebody walked in front of you to get to you," Burroughs said. "So it makes it that much more sweet."
David Hernandez pitched a scoreless eighth, and things got testy in the bottom of the inning when Parra tripled off Huston Street and tried to score on a throwing error to third base. He was cut down by a good five feet, knocking over Alfonzo at home plate in the process.
Parra and Street had words, while a few players from each side left their dugouts.
"I think Street was a little bit sensitive because Parra hit a triple," Montero said. "So he got a little bit upset, but it's nothing personal."
Street said it was all in the heat of the moment.
"I just felt like yelling at somebody," Street said. "I like Parra as a player. I've got a lot of respect for him. He plays the game hard. He wasn't doing anything dirty."
J.J. Putz sealed Arizona's 12th consecutive home win and undefeated homestand with a scoreless ninth inning for his 35th save of the year.
"It was just a very good homestand," Gibson said. "We played really good at home. Really good."
But now the D-backs travel to San Francisco, where the defending World Series champions await with a win-or-go-home mentality to keep their season alive.
"They're the defending champs," Montero said. "But I think they already played for that."
Anthony Fenech is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.