Belarus took the lead in the second period of the quarterfinals with two goals from Ruslan Salei and Konstantin Koltsov, before Russia's Vitaly Proshkin clawed one back in the 25th minute.
Eleven minutes later defenseman Vitaly Atyushov leveled the game and within 30 seconds Alexander Frolov had put the defending champions 3-2 ahead.
Russia barely had any time to enjoy their lead, however, before Belarus' Salei got his second in the dying moments of the period to level the score 3:3.
Seven minutes into the third period Ilya Kovalchuk's strike put Russia ahead 4:3. They managed to hang onto the narrow lead to put Belarus out of the tournament and will now face either the U.S. or Finland who play each other later tonight.