Banks pitched in place of Bud Norris, who was sick with the flu. The Astros have thrown three shutouts in 15 spring training games.
Toronto's scheduled starter, Brandon Morrow, also was scratched after feeling soreness in his right shoulder while warming up.
Potential Astros closer Matt Lindstrom struck out two in an inning. He has pitched 5 2-3 scoreless innings in five appearances.
Cory Sullivan homered off Blue Jays starter Stephen Register.