The Americans were undefeated heading into the matchup, while head coach Radim Rulik's squad had just one victory in preliminary-round action.
Czechia was also coming off a disappointing 5-2 loss to the Latvians.
"I think we learned a lesson against Latvia," said Mysak,
as reported by Andrew Podnieks of IIHF.com
. "We learned a lesson that they just wanted it more than us. So we lost. Today, we tried to do the same. We just wanted it more, and that's why we won. We just blocked the shots. We ate pucks, and we had success."