Shemyakina began fencing in the senior category in the 2002–03 season. She climbed the podium at her second World Cup event with a bronze medal in Katowice. This result had her selected into the senior national team at the age of seventeen for the 2003 World Fencing Championships. She created a surprise at the 2005 European Championships by reaching the final after defeating Romania's Iuliana Măceșeanu. She then prevailed over Hungary's Hajnalka Tóth to win her first major title.