Jack Defty settled this early on with the only goal of Saturday's game – just as he did in the reverse fixture at Hitchin in August, as Lynn claimed a double.
Lynn, without Matt Nolan (who had a virus), were anything but convincing. However, they remained in third place and primed for a play-off spot after this win.
Lynn boss Keith Webb said: "It was a scrappy affair and we should have taken more of our chances in the first half when, in patches, we played well.
"The most important aspect for me is that we have now taken four points from our last two games.
"At this stage of the season, three points is three points and that's all that concerns me.
"There are people moaning about players and their performances, but supporters must realise that now it's a different situation and different environment. There is an awful lot of pressure on the players to do the business."
The first chance of the afternoon in the seventh minute fell to Steve Melton, who nodded wide at the near post a Matt O'Halloran free-kick.
The Canaries hit back courtesy of a high, bobbling ball which Gavin Jaggard latched on to ahead of Mark Warren, but the striker shot straight at Lynn keeper Scott Howie.
Moments later, in the 17th minute, came the decisive goal.
Dean West sent a looping, hanging cross from the Lynn right which deceived away keeper Rob Beckwith and his defence, who must have thought it was going out.
After what seemed like an age, Defty's wait at the far post was worth it as he headed home almost on the goal-line.
Midway through the half Defty directed another effort, this time at the keeper, from a Louis Blois centre.
The only other incident of note in the opening 45 minutes was O'Halloran rolling the ball past the onrushing Beckwith, only to go inches wide.
Little happened in the second half for The Walks outfit, who failed to test Beckwith.
Early doors, Ryan Charles shinned one wide from 20 yards, and with ten minutes to go Jon Stevenson sent an overhead kick off target.
The more the game went on, the more pressure Hitchin put on, culminating in the final ten minutes.
Sub Charlie Defty heroically played on despite getting twice whacked in tender parts by the ball.
In injury time, Howie denied Charles and then dealt with an in-swinging Adam Cunnington corner. Andrew Fisk then showed pace and determination to close out the threat and ensure a vital three points.
Hitchin, who had already sold key frontman and Lynn target Chris Dillon to Histon, rued the lack of a cutting edge.
Lynn: Howie, West, Blois, Warren, Crane, Fisk, O'Halloran (Gould 76), Camm (C. Defty 72), J. Defty (Frew 61), Bloomfield, Melton. Subs not used: Hammond, Marshall.
Hitchin: Beckwith, Deeney, Childs (Orphanu h-t), Gentle-King, Frater, Stevenson, Lamacraft, Standen, Jaggard (P. Scanlon 78), Charles (Cunnington 54), A. Scanlon. Not used: Cretton, Darkin.
Booked: Stevenson 41.
Att: 857. MoM: Mark Warren. Referee: D. Plowright (Mansfield).