BRATISLAVA, May 21 (Xinhua) -- Russia defeated Sweden 7-4 on Tuesday night and kept a perfect record in the round robin stage of Group B at the IIHF Ice Hockey World Championship.

Russia took its time to answer Gabriel Landeskog's opening goal, but when the Red Machine started rolling, there was no stopping it.

An astounding six goals ended in Jacob Markstrom's net from 20 shots in the second period. Artem Anisimov, Yevgeni Dadonov, Alex Ovechkin, Kirill Kaprizov, Mikhail Grigorenko and Evgeni Malkin scored one each to give Russia a dominant 6-1 lead.

After the crushing second period, the two-time defending champions tried to mount a comeback in the third. William Nylander's goal from the slot, Oliver Ekman-Larsson's own rebound, and John Klingberg powerplay wrister were not enough, however.

Russia remain undefeated in Group B and will face the United States, the fourth team in Group A, in the quarterfinals in Bratislava.

Sweden concluded their preliminary stage in third spot and will challenge Finland in a Nordic derby quarterfinal in Kosice.