Both Crawley and City had assured their League One status and, in an even opening, home skipper Josh Simpson had a shot from the edge of the area turned round the post by keeper Simon Moore.
The Red Devils went in front after 25 minutes when a corner from Andy Drury was not cleared and striker Proctor beat Moore from 12 yards with a volley which took a deflection.
Moore was well positioned to hold a low drive by Drury before being called into action again to keep out an effort from Gwion Edwards.
City striker Tyrone Barnett had a low shot easily saved after the break before Moore swooped to save a free-kick from Matt Tubbs.
Tubbs should have increased Crawley's lead when he burst into the area but wastefully put his shot wide.
City midfielder Gillett, on loan from Nottingham Forest, equalised on 62 minutes in front of 1300 travelling fans by firing into the bottom corner from the edge of the area.