Niwatana Sesawasdi started his football career as a goalkeeper whilst at primary school before becoming a striker at high school, helping the team to win three consecutive provincial junior championships. Sesawasdi studied at the National Institute of Physical Education and Sports University, playing in their football tournament. By the early 1960s he had joined Raj-Vithi F.C. in Bangkok before playing with Port F.C. From 1966 to 1979 Sesawasdi played for the Thailand national football team, making 85 appearances and scoring 55 goals. He was part of the national squad that competed at the 1968 Mexico City Olympics, and he won the King’s Cup in 1976.