Humm scored her first goal in the 47th minute off a powerful strike from outside the penalty box. All three of her goals would come within six minutes early in the second.
Bachmann finished off Switzerland's scoring in the 81st minute with its 10th goal.
Eseosa Aigbogun and Martina Moser also found the back of the net for the Swiss, who got their first win of the tournament.
Angie Ponce scored for Ecuador — its first World Cup goal — on a penalty kick in the 64th.
In other Group C action, Aya Sameshima scored in the 6th minute as Japan edged Cameroon 2-1 to become the first team to secure a berth in the knockout stage.
Yuika Sugasawa added the other with a header off a cross for Japan, which are the defending champions.
Ajara Nchout responded for Cameroon in the 90th minute. Cameroon almost tied the game in stoppage time, but a shot from Gaelle Enganamouit just missed to the left.
Japan has six points and are atop the group at 2-0-0. Switzerland and Cameroon are in second at 1-0-1 while Ecuador is 0-0-2.
Earlier, Kyah Simon had a pair of goals as Australia blanked Nigeria 2-0 in Winnipeg.
Simon received a feed from Lisa De Vanna in the 29th minute and beat Nigeria goalkeeper Precious Dede. She scored again in the 68th after being left unguarded in front of the net.
Australia improves to 1-0-1 with three points in Group D with the win. Nigeria is in last place in the group at 0-1-1.
The United States remain atop the Group D standings after a 0-0 draw against Sweden.
The U.S. is ranked No. 2 in the world and were playing against former coach Pia Sundhage.
American Abby Wambachhad a header pop up and over the crossbar in the 72nd minute after being substituted into the game.
The U.S. has four points at 1-1-0 while Sweden has two at 0-2-0.