Pak won the Pyongyang Marathon on 13 April 2014 with a personal best of 2:12:26. The winning time was an improvement of more than a minute from his previous personal best which earned him the fifth place in the same race in 2013.[3] In 2015, he came second in the 15th Asian Marathon Championship in Hong Kong with a season's best[4] of 2:16:09.[5] He took part in the marathon at the 2015 World Championships in Beijing the same year and placed 11th with a time of 2:15:44, a new season's best.[6]