Left-handed batters were hitting 1-for-23 against Duffy this season with a .197 on-base-plus-slugging percentage.
"This guy, he's been tough on lefties," Porter said. "We're going to run that right-handed lineup at him and see if we can score some runs."
Carter, who sat out the last three games, served as the designated hitter, while Corporan and Guzman slotted into catcher and first base, respectively.
George Springer immediately got the Astros on the board in the first inning of their 9-3 victory with a two-run home run off Duffy, his ninth of the season and sixth in as many games. Carter clubbed a solo home run in the fifth inning, then added a three-run shot off right-hander Louis Coleman in the sixth. Corporan had an RBI double in the third.
The Astros chased Duffy in the fifth, touching the lefty for six runs (five earned) on seven hits and drawing five walks.
Brian McTaggart is a reporter for MLB.com and writes an MLBlog, Tag's Lines. Follow @brianmctaggart on Twitter. Jackson Alexander is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.