[3] He is one of the coaches of the Russian women's national chess team.

Riazantsev won the World Youth Chess Championship in the U12 section in 1997, and the European Youth Chess Championship in the U14 division in 1998.

In 2005, he won the Stork Young Masters tournament in Hengelo on tiebreak from Andrey Zhigalko, Vladimir Belov and David Baramidze.

[5] In 2010, Riazantsev tied for 1st–7th places with Vitali Golod, Nadezhda Kosintseva, Leonid Kritz, Sébastien Feller, Christian Bauer, Sébastien Mazé in the Master Open at the 43rd Biel Chess Festival, winning the event on tie-break score.

In September 2011, Riazantsev was appointed Russian national team coach.