At a fog-bound Steel Park the game was just about playable following earlier work on the pitch by groundstaff, writes Stewart McNeill.
The NPL South clash was 9th against 5th and the away side did better before the break with Fortnam-Tomlinson turning home a corner at the far post just after the half-hour mark to give Stamford a 1-0 lead.
Corby rallied in the second half with a series of corners putting pressure on Stamford before a late challenge in the box saw a penalty awarded - but Jordan Crawford's shot was saved.
Corby salvaged a point with a goal three minutes from the end - a centre turned in on the line by substitute Ryan Bell.
The Steelmen have three games left in the league season to finish as high as they can before decisions are taken on which league they are placed in for the next campaign.
437 saw this game at Steel Park - on Saturday ( Apr 14 ) Corby Town are at Newcastle Town.
On Tuesday S & L FC's game at Bourne Town in UCL Division One was postponed due to waterlogging.