HOUSTON -- Houston third baseman Luis Valbuena, whose all-or-nothing production perfectly embodies the perception of the Astros' boom or bust offense, delivered more of the pop that makes them so lethal.

Valbuena belted two home runs to pace another power-laden offensive attack as the Astros rallied from an early deficit to defeat the Colorado Rockies 8-5 on Tuesday at Minute Maid Park.

Valbuena homered twice against Rockies left-hander Chris Rusin (2-2) to increase his team-leading total to 16. Valbuena took Rusin the opposite way to left field for a solo homer with one out in the second inning before adding a three-run blast that capped a five-run second.

Valbuena's batting average remains below the Mendoza Line (.188), but his pop near the bottom of the order -- he batted eighth -- serves as a rare asset.

"He's hitting down at the bottom of the order (and) leads our team in home runs," Astros manager A.J. Hinch said. "That type of potent bat at the bottom, you can't fall asleep at the bottom of our order or he'll change a score."

The Astros (38-28) claimed the first two games of this split four-game set, with both teams set to resume the series in Denver on Wednesday. Colorado (28-36) dropped its 13th consecutive interleague road game.

"These guys, they hit the ball out of the park," Rockies manager Walt Weiss said. "You keep them in the park, you got a pretty good chance of beating them. They score a lot of runs with the home run. That's what they did again."

Astros catcher Hank Conger added a home run in the fifth inning, his fourth of the season, off Colorado right-hander Brooks Brown, providing a timely answer to the Rockies' two-run rally in the top of the inning.

Colorado right fielder Carlos Gonzalez supplied both runs with his two-run shot off Astros rookie right-hander Vince Velasquez, a 417-foot blast into the upper deck in right that chased Velasquez from the game.

Gonzalez just missed matching Valbuena with a second homer in the seventh. His drive down the right-field line off left-hander Tony Sipp was initially ruled fair, but his 10th homer of the season was erased after a replay review determined that the ball traveled foul. Gonzalez later struck out.

"The ball was fair coming off the bat," Gonzalez said. "It was really fair and then at the end it started fading away. I think (umpire Bob Davidson) said it was a fair ball because it was really hard to tell at the beginning.”

The Rockies seized a 3-1 lead in the second when catcher Michael McKenry, second baseman DJ LeMahieu and center fielder Charlie Blackmon delivered RBI singles.

Velasquez recovered to retire eight of the next 10 batters, issuing two walks during that span. But after striking out shortstop Troy Tulowitzki twice, Velasquez surrendered a two-out single to Tulowitzki in advance of the Gonzalez two-run homer.

The Astros' outburst in the third came with two outs as Conger and left fielder Domingo Santana preceded Valbuena with run-scoring, two-strike singles, with Santana getting the first base hit of his career.

"It felt really fantastic," said Santana, who finished 0-for-17 with 14 strikeouts during his first two stints with the Astros last season. "It felt like a whole building got off my shoulders. It really felt good."

Right-hander Luke Gregerson worked a perfect ninth for his 17th save of the season. Astros right-hander Will Harris (3-0) posted the win.

NOTES: A New York Times report revealed that the FBI is investigating front office officials with the St. Louis Cardinals for hacking into the Astros' internal network last season to steal information on player personnel. The Astros suffered a significant breach of their "Ground Control" database last summer. Both the Cardinals and Astros said through team-issued statements they are cooperating fully with