In his final season for Chesterfield, 2012–13, Lester played the majority of his games from the substitutes bench. He made only 11 starts despite figuring in 38 games in all competitions. Regardless of this his score rate is still impressive, having bagged 11 goals from just 1,454 minutes of football (the equivalent of just over 16 full games). Jack played his last game for Chesterfield, and his last game in professional football on 27 April 2013. He scored twice as The Spireites won 4–0 in a game that was a "fitting send off for a player who will forever be remembered by the Chesterfield faithful". His legendary status is regularly referred to by the club and fans and in August 2013, Chesterfield announced that the number worn by Lester throughout his time with the club, 14, would be retired in his honour.