DENVER -- A combination of power and small ball helped the Houston Astros break open a tight game in the late innings.
J.D. Martinez hit a go-ahead RBI single in the eighth inning, Carlos Pena connected for a home run as part of a three-run ninth, and the Astros rallied against Colorado's bullpen to beat the Rockies 6-3 on Wednesday night.
The Astros overcame 12 strikeouts and Troy Tulowitzki's first multihomer game since 2011 in taking the opener of a two-game interleague set at Coors Field.
Leading 3-2, Houston got a boost when Pena started the ninth with his fourth homer, driving a full-count offering from Rob Scahill over the right-field wall.
Trevor Crowe followed by beating out an infield single and one out later, pinch-hitter Jimmy Parades singled to left, advancing Crowe to third. Marwin Gonzalez followed with a safety squeeze, laying down a sacrifice bunt as Crowe broke for the plate and scored.
"It was absolutely perfect," Crowe said. "I felt like the last 15 steps, I walked home because the bunt could not have been better. On a safety squeeze, you want to roll it down the first-base line and Marwin was able to do that."
Brandon Barnes singled to drive in the inning's final run for the Astros.
"That was good baseball there," Astros manager Bo Porter said. "The three runs in the ninth were huge in this ballpark. Guys did a great job. Getting the sacrifice bunt down, Trevor going first to third and Gonzo, great job with the safety squeeze and the two-out RBI was huge. A four-run lead here is really a two-run lead."
Paul Clemens (3-2) pitched 1 2/3 innings of scoreless relief.
Gonzalez led off the eighth with a single off reliever Edgmer Escalona (1-2). Jose Altuve was intentionally walked and Rex Brothers relieved Escalona. Brothers struck out Jason Castro but Martinez hit a two-out single up the middle, scoring Gonzalez to put the Astros in front by a run.
"This guy's a run producer," Porter said of Martinez. "He's one of those guys, when there are RBIs out there, he smells them. He's put together some of his best at-bats with runners in scoring position."
Colorado had runners on first and second with two outs in the bottom of the eighth, but first baseman Pena made a diving catch of Jordan Pacheco's liner to end the threat.
"Of course it's frustrating, but that's how baseball goes," Pacheco said. "We've just got to keep swinging, keep getting guys on."
The Rockies couldn't take advantage of a solid start from Tyler Chatwood, who struck out 10 batters in six innings.
"Tyler did a great job," Rockies manager Walt Weiss said. "We didn't get the big hit to get the big inning. But Tyler certainly did his part."
The strikeout total was the most in a game by a Rockies starter this season and a career high for Chatwood, who allowed two runs on four hits.
"I think I was getting ahead and I was able to put some guys away with my slider," Chatwood said. "Me and Jimmy (Wright, Rockies pitching coach) worked on it in our last side session. It's been kind of inconsistent, but I found it tonight."
Bedard also pitched well and did not get a decision. He went six innings and allowed two runs on seven hits. It was the third consecutive outing in which he has allowed only two runs.
Houston struck first, getting a run in the second inning on Matt Dominguez's sacrifice fly.
Tulowitzki answered leading off the fourth, when he drove the first offering from Bedard the opposite way into the right-field seats. It was his 11th home run of the season and also produced the 500th run scored of his career.
Tulowitzki's two-out double in the fifth drove in Pacheco. But the Astros tied it up at 2-all in the sixth when Barnes scored on a sacrifice fly by Castro.
Chatwood escaped further damage in the inning when he fanned Martinez and Pena for his ninth and 10th strikeouts of the game. His previous high for strikeouts was six.
The Rockies recalled Scahill from Triple A Colorado Springs and made room for him by optioning OF Charlie Blackmon. ... Colorado stranded 12 baserunners. ... The Rockies are six games into a stretch in which they play 17 games in 17 days. ... The Astros, whose Triple-A affiliate is in Oklahoma City, raised $21,000 this week through the Astros Foundation to aid Oklahoma's tornado relief efforts. The money is being forwarded to the Red Cross. ... The Rockies acquired Chatwood two years ago from the Angels in exchange for catcher Chris Iannetta. ... Martinez has had back-to-back games with multiple hits.