Shawn Hill allowed three hits in five innings and four relievers completed the shutout. Canada improved to 3-0.
"We're really confident," catcher Pierre-Luc LaForest said. "We've accomplished what we want to do so far. We're in the groove now."
Orr's homer came in the second inning and produced Canada's first three runs. LaForest added a solo homer leading off the third and Stubby Clapp had a a solo shot during a three-run fourth.
Canada will next play Greece, which is winless in three games after dropping a 7-1 decision to Taiwain on Tuesday.
Cuba and Japan were unbeaten in two games going into their Tuesday night meeting.