Internationally Riazantsev played for the Russian national team at the 2005 World Championship, winning a bronze medal.

In January 2012, Riazantsev took a shot in a skills competition that measured a speed of 114.1 miles per hour.

The National Hockey League does not recognize this feat, as the puck travels a shorter distance to the goal net in KHL competitions than in those of the NHL.

On June 11, 2013, Riazantsev was traded by Severstal to return to his original club, Spartak Moscow, in exchange for Nicholas Bushuev.

[3] On October 4, 2014, Riazantsev continued his journeyman career when he was traded after only 8 games in the 2014–15 season with HC Neftekhimik Nizhnekamsk to Amur Khabarovsk.