Memorably, he caught a nineteen-yard touchdown pass to clinch the Gators' 17–7 upset win over the ninth-ranked Penn State Nittany Lions in the 1962 Gator Bowl,[4] intercepted a third-quarter Joe Namath pass to help preserve a 10–6 upset of the third-ranked Alabama Crimson Tide in Tuscaloosa in 1963,[5] and ran for a seventy-yard touchdown to provide the margin of victory in the Gators' 27–21 win over the Miami Hurricanes later that same season.
[3] Clarke led the Gators in punt return yardage in 1961 and 1962, and was the recipient of the Gators' Fergie Ferguson Award, recognizing the "senior football player who displays outstanding leadership, courage and character," in 1963.
"[7] Clarke was selected by the San Francisco 49ers of the National Football League (NFL) in the seventh round (85th pick overall) of the 1964 NFL draft,[8] but signed with coach Lou Saban's Buffalo Bills of the alternative AFL, and played his entire five-year career as a safety and punt returner for the Bills from 1964 to 1968.
[12] Statistically, Clarke's best season was 1965, when he had seven interceptions and played in the AFL All-Star Game.
[14] In 1968, his final season with the Bills, Clarke had an 82-yard punt return for a touchdown against the New York Jets.