Majewski was born in a sport-loving family: his mother was a gymnast and his father a fencer. He himself took up fencing under the direction of his uncle and godfather Piotr Majewski. He earned a bronze medal in the 2006 Junior European Championships in Poznań. In seniors, he climbed his first World Cup podium with a bronze medal in the 2006 Vancouver Grand Prix. He joined the national team that same year and won with them a silver medal in the 2006 European Championships. On his way back at the airport he was involved in a scuffle with a Turkish official and spent two months in prison.