One of the ways a worse team on paper can beat a better team is by taking away the other team's time and space. Every time a player on the better team touches the puck, you need to go after him and get your stick on the puck and force him to make a play. You force mistakes and limit the ability to make plays.

Unless you are insanely skilled and respected, if you try to slow down, the other team will simply lunge at you every time you get the puck and pressure the shit out of you. You need to make plays at high speed, or the other team is simply going to start pressuring and playing aggressive defense. You see a good team lose to a bad team because the bad team is aggressive and playing at high speed and the "better" team is caught on their heels.