Skidding right-hander Lucas Harrell can pitch the Houston Astros to a rare series sweep on Thursday night when they return to Coors Field to finish a two-game set with the Colorado Rockies.
In Wednesday's opener, J.D. Martinez knocked in the go-ahead run in the eighth inning, as Houston used a late charge to take down Colorado, 6-3.
Carlos Pena homered and Brandon Barnes added an RBI single in a big ninth inning for the Astros.
"The three runs in the ninth were huge in this ballpark. Guys did a great job," Astros manager Bo Porter said.
Paul Clemens (3-2) tossed 1 2/3 innings of scoreless relief for the win.
Troy Tulowitzki finished with three hits, including a pair of solo homers, and drove in all three runs for the Rockies, who lost for the fourth time in five games.
"This is a good team who can really put some runs on the boards. It's just not happening right now," Colorado outfielder Carlos Gonzalez said.
Edgmer Escalona (1-2) was charged with the lead run in his 1 1/3 frames.
Harrell, who'll turn 28 next week, was 3-2 on the season after defeating the New York Yankees, 9-1, on April 29.
He's winless in May, however, dropping four decisions in five starts while his earned run average has swelled from 3.60 to 5.43.
He was shelled for six runs in just 1 2/3 innings of his most recent start, an 11-5 home loss to Oakland on May 25.
Harrell is 1-2 in three career meetings with the Rockies.
Colorado goes with Dominican righty Juan Nicasio, who hasn't lost in his last two starts after going three straight outings without a victory.
Nicasio defeated Arizona, 6-3, on April 26, then went 0-1 in his initial three May starts before rebounding to beat San Francisco, 5-0, on May 19.
He allowed five hits in six scoreless innings against the Giants in that start, then faced them again six days later and allowed two runs on seven hits in five innings - while getting a no-decision in Colorado's 6-5 loss.
Nicasio has a pair of no-decisions in two career meetings with Houston.
The Rockies won five of seven games from the Astros in both 2011 and 2012. Houston last won the season series, 4-2, in 2010.
Houston leads the all-time series by two games, 82-80, since 1993.