Christen Press scored her third goal in as many games in the 70th minute before McDonald’s goal in the 72nd to make it 6-0. Tobin Heath, who came in as a substitute, added a no-look goal and Horan capped the scoring by completing her hat trick in the 81st.
The crowd at Houston’s BBVA Compass Stadium was announced at 14,121.
The top-ranked U.S. team also defeated Haiti 4-0 in the group stage opener on Tuesday night. The Americans face Costa Rica in their group final on Monday.
Costa Rica down Haiti 2-0 earlier Friday at for its second win in the group.
Eight teams are playing in the tournament, with the top two teams from each group advancing to the semifinals in Carson, California, on Feb. 7.
The top two finishers in the tournament will earn the region’s berths in the Tokyo Games this summer.