The Group A match in the Czech Republic saw the holders take complete control in the first period goals from Maureen Murphy and Natalie Heising coming just 34 seconds apart as they moved into a 2-0 lead.

Their captain Cayla Barnes would then take centre stage, with the American scoring on her 18th birthday at the start of the second period.

A goal from Taylor Wente and a second from Barnes saw the United States move further out of sight, before Anneke Linser made it 6-0 in the third period.

Daria Beloglazova scored a consolation goal for Russia in the closing seconds, but it was the American team who made a sterling start to the competition as they chase a sixth title.

Last year’s beaten finalists Canada got their campaign off to a fine start as they defeated Sweden 5-1 in the day's later game.

Group A features the best four teams as last year’s event in St Catharines, Canada, with the top two at the end of this stage progressing to the semi-finals.

The bottom nations will move into the quarter-finals, where they will face the best two finishers in Group B.

Hosts the Czech Republic began impressively in the group, as they won a thrilling match against Japan by a 3-2 scoreline.

Having trailed 2-1 heading into the third period, goals from Krisyna Kaltounkova and Natalie Mlynkova saw the Czech team complete a comeback victory.

Finland would also earn victory on the first day of the tournament, as they defeated Switzerland 3-1 in the other match in Group B.