[3] He competed with his birth name Emil Andersson until 2009, when he married and chose to acquire the surname of his wife Martinsson, as permitted by Swedish law.
He defeated top seed Vladyslav Prianishnikov in the semifinal (6–3) and then scored seven straight tens in the final, winning it with 6–1 over Miroslav Januš.
Martinsson defeated his title at the 2009 World Running Target Championships, once again scoring straight tens in the final.
Prior to this, Martinsson had won two individual world championship medals: a silver in 50 metre running target mixed at the 2002 ISSF World Shooting Championships and a bronze in 10 metre running target mixed in 2008.
He also participated in the last Olympic running target competition which was held in 2004, reaching the final and finishing fourth, missing the bronze medal by 0.3 points.