There were six different scorers for the US with Hilary Knight, Megan Keller, Tessa Janecke, Abby Roque, Eden Lacey and Hayley Scamurra all netting.

Goaltender Aerin Frankel made 22 stops for the Americans.

Sara Cajanova and Denisa Krizova scored for the Czechs who are third in the group.

They did lead 2-1 during the first period but the US took control soon after.

Czech goaltender Blanka Skodova made 23 saves as she tried to keep her nation afloat.

The US now sit top of the Group A standings with three wins and a goal difference of 18, with Canada also having three wins and a goal difference of 13.

In Group B, Finland made it three wins from three following a 4-2 victory over Sweden.

Sweden went 2-0 up but in the third period Finland began to turn the tide, scoring all their goals in the final stanza.

A double by Ronja Savolainen along with goals from Viivi Vainkka and Petra Nieminen guided Finland to victory.

Finland's goaltender Anni Keisala had 13 saves while Sara Grahn of Sweden had 34.

Elsewhere in Group B, Germany swept past France 3-0 to make it two victories as the latter remain without a win.

France outshot the Germans 28-26 but were unable to score past Sandra Abstreiter.

The competition continues tomorrow at the CAA Centre in Brampton, with Switzerland facing Japan in Group A with both looking for a first win. 

Hungary and Finland square off in Group B with the Finns aiming to complete a 100 per cent record in the opening stage.

However the most exciting match-up will be a rematch of last year's final between the US and Canada, who will each be looking to take top spot in Group A.

All five teams in Group A will reach the quarter-finals as it is the designated stronger pool.

The top three teams in Group B will join them.