The 37-year-old striker, who announced his retirement on Friday, marked his 395th and last League game by taking his tally to 149 with a penalty and a typically cool finish with Jay O'Shea and Marc Richards also getting on the scoresheet.
Lester led Chesterfield out but it was O'Shea who sparked the game into life with a spectacular 25-yard shot into the top left corner in the 22nd minute.
Richards headed in a free-kick in the 31st minute before Lester gave the home fans the goal they had come to see when he converted a 34th minute penalty after he was tripped by Jordan Moore-Taylor.
Exeter rarely threatened Chesterfield and they were four down on the hour when Lester was put through to place a right foot shot into the bottom corner from 12 yards.
Lester made his exit to another standing ovation 15 minutes from the end when he was substituted and Richard O'Donnell denied Exeter a consolation with three smart saves in the closing minutes.