Dom Nunez also hit a home run for the Rockies, who snapped a nine-game losing streak to the Astros.
Carlos Correa and Aledmys Diaz had RBI doubles for the Astros, who have lost eight of nine.
''We're all competitors in this clubhouse, so it was nice coming off the off day to get one there,'' Cron said of the Rockies, who entered with the worst record in the majors. ''Jon threw the ball great. We got him some runs there late in the game. I think overall it was something we could for sure build off of.''
Gray (2-1) had some control issues, walking four in his 6 2/3 innings, but allowed just three hits and one run. He struck out six and benefited from a defense that turned three double plays.
Gray said he has come to relish his outings at Coors Field, and he has put up solid numbers in a park more typically known for bringing out the best in hitters. He's just the third pitcher in franchise history to pitch five or more innings and allow one or no runs on four or fewer hits in three straight starts at Coors Field.
''I love pitching at Coors,'' Gray said. ''I have all the confidence in the world, pitching here. I have plenty of experience and I just see it as a strength to be able to start at home.''
Houston starter Luis Garcia (0-1) was trying to protect a 1-0 lead in the sixth when he gave up a two-out bloop single to Trevor Story.
Garcia then threw what initially was called a wild pitch by plate umpire Ryan Wills. But the Rockies challenged and a replay review determined that the pitch had brushed Charlie Blackmon's shin, and he was awarded first base. Bryan Abreu relieved and Cron greeted him by lining a double over the head of center fielder Myles Straw, scoring Story and Blackmon to put the Rockies up by one.
Cron connected off reliever Joe Smith in the bottom of the eighth for his first homer of the season, a three-run shot that sailed into the left-field bleachers.
''Abreu had a slider that hung right in the middle of the plate,'' Astros manager Dusty Baker said. ''Joe got a slider that hung right over the plate and in the big leagues when you make mistakes like that, it's going to cost you. We just made some mistakes over the heart of the plate.''
Nunez hit a solo shot in the seventh off Ryne Stanek.
Garcia went 5 2/3 innings and allowed two runs and three hits. He struck out six.
MINOR LEAGUE DEAL
The Astros' acquisition of the minor league Sugar Land Skeeters was approved Tuesday by local officials in the Texas city. The action finalized the Astros' acquisition of a majority interest in the team, which will serve as their Triple-A affiliate. The city and the Astros also agreed to a lease extension keeping the club at Constellation Field through 2045.
Astros: INF Alex Bregman, C Martin Maldonado, DH Yordan Alvarez and INF Robel Garcia have rejoined the club after being activated from the COVID-19 injured list (health and safety protocols). C Garrett Stubbs was optioned to the team's alternate training site, and INF Alex De Goti and OF Ronnie Dawson were returned to the alternate site. INF Taylor Jones was placed on the injured list. ... INF Jeremy Pena, one of Houston's top prospects, is slated to undergo surgery Wednesday to repair a left wrist injury he suffered at the alternate training site. He is expected to be sidelined about five months.
Astros: RHP Jose Urquidy (0-1, 4.50 ERA) is set to make his fourth start of the season and first of his career against Colorado in Wednesday's series finale.
Rockies: LHP Austin Gomber (0-2, 3.52 ERA), who arrived in Colorado as part of the trade that sent Nolan Arenado to St. Louis, seeks his first win as a member of the Rockies.
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