Sestak was a starter in his rookie year and, until a series of knee injuries ended his career after the 1967 season,used his strength to dominate the line of scrimmage. Sestak was a three-time selection to All-American Football League teams and a unanimous All-AFL defensive tackle in three consecutive years; 1963, 1964 and 1965. Sestak served as the cornerstone of a defense that took the Bills to the playoffs four straight years (1963–1966) and consecutive AFL championships in 1964 and 1965. Over the 1964 and 1965 seasons, Sestak and his defense mates held opposing rushers without a touchdown for seventeen consecutive games, a Professional Football record that still stands. Twice during his outstanding career he realized the defensive lineman's "dream", returning interceptions for touchdow