Gills keeper Simon Royce was called into action after nine minutes of Saturday's League Two clash at Priestfield when he parried Glynn Hurst's half-volley after being set up by strike partner Andy Bishop.
Minutes later, the home side's top scorer Simeon Jackson thought he had won a penalty after going down under pressure from former team-mate Efe Sodje but his appeals were waved away.
The lively Mark McCammon came close to breaking the deadlock for the home side after 20 minutes but his header from John Nutter's corner was blocked by keeper Wayne Brown.
The home side continued to threaten, and just before half-time on-loan midfielder Josh Wright tested Brown with a low drive. On the hour Jackson raced onto Curtis Weston's through ball and, from a tight angle, flashed a shot just wide of the far post.
And with 20 minutes left, Stuart Lewis came agonisingly close to giving the Kent side the crucial win when he struck the upright with a stinging volley.