On 6 June 2009 Krpálek won his first senior Grand Prix tournament in Bucharest. In August the same year he participated in his first World Judo Championships, held in Rotterdam that year. He was defeated in the first round by the French judoka Cyrille Maret. Later in 2009 Krpálek was defeated in the final of the Junior European Judo Championships by Elmar Gasimov of Azerbaijan, who would become his great rival at senior level. However Krpálek became the world junior champion again that year. His biggest rival in 2011 was the Japanese judoka Takamasa Anai. He defeated Krpálek in the final of Grand Prix in Düsseldorf and later in the World Championships in Tokyo again, this time in the third round. At the European Championships in 2011 Krpálek placed fifth after being defeated by two Georgian judokas. In June he won three Grand Prix tournaments in a row and became the first Czech judoka since the independence of the country to win a medal at the World Judo Championships, when he won a bronze medal in Paris.