In the senior category Blaszyck won in 2010 the French national championship after defeating World no.5 Gauthier Grumier in the final. He also won the team event with the Levallois Sporting Club. In the 2012–13 season he climbed his first World Cup podium with a bronze medal at the Qatar Grand Prix in Doha. He reached the final in the Trophée Monal at home in Paris. After leading 14–13 against fellow Frenchman Daniel Jerent, he struck a hit that was later annulled for technical reasons, then lost the match. These two results caused Blaszyck to be was selected for the team event of the Zagreb European Championships. France were defeated by a single hit by Switzerland in the semifinal, then lost to Ukraine and finished fourth. In July he earned a team gold medal at the 2013 Summer Universiade in Kazan. A few weeks later, at the 2013 World Championships, his first participation to the competition, he was eliminated in the second round by Poland's Radosław Zawrotniak. In the team event France lost to Ukraine in the semifinals, but prevailed over Poland to win a bronze medal. Blaszyck finished the season World no.12, his best ranking .