Vodopyanov won the silver medal at the 2004 Junior World Championships, where he lost to Hungarian Pál Bedák.

In 2006 he won the silver medal at flyweight at the Russian Championships, losing to three-times European champion Georgy Balakshin of Russia.

At the 2006 Junior World Championships he made an early exit against eventual champion Vasyl Lomachenko.

In Chicago at the 2007 World Amateur Boxing Championships the 20-year-old beat local hero Gary Russell Jr. 16:6 and Puerto Rican McJoe Arroyo 20:9 to reach the finals.

The judges awarded the fight to Kumar with the scores tied 9-9 after four rounds, ruling that the Indian fighter had landed the most punches.