Lynn failed to turn their possession into goals against fellow play-off hopefuls AFC Rushden & Diamonds on a heavily sanded Hayden Road pitch where the conditions did not aid good football.
Early chances fell to Lynn with Adam Marriott shooting over from the edge of the box on three minutes and then Ryan Fryatt getting on the end of a Michael Clunan free kick but seeing his close-range header saved by Ben Heath in the Diamonds' goal.
Diamonds responded with a Declan Rogers free kick from 35 yards which Alex Street clutched at the second attempt.
Craig Parker, given a start at the expense of Ryan Jarvis, was next with an effort for Lynn but his shot was deflected by Heath into the side netting.
With nineteen minutes gone Parker had another attempt from distance but this time it went narrowly wide.
The following minute saw the home side's Zac Reynolds try his luck from the edge of the area but it too went wide.
Marriott produced a couple of opportunities for Lynn and then at the other end Street was called upon on just before the half hour mark to push a Declan Rogers free kick round he post.
What turned out to be the deciding goal arrived on 39 minutes. A Lynn clearance only found Diamonds' Joe Curtis who headed forward for Tom Lorraine to hold off the attentions of Rory McAulay to put the ball past Street for his 20th goal of the season.
Lynn had the perfect opportunity to level matters just before the break when Frazer Blake-Tracy's corner was missed by Heath and fell to Michael Gash at the far post but he somehow shot wide from 8 yards.
Lynn controlled the second half but failed to produce many chances against a well organised and disciplined Diamonds defence with Lynn being guilty of too many over-hit corners and free kicks.
Gash saw an early header saved and, on 57 minutes, Marriott shot wide from close in and in the following minute Parker was denied a certain goal by the intervention of Alex Collard who produced a great block.
Lynn substitute Ryan Hawkins shot over from distance and Gash tried to snatch at the ball only to see it roll wide of the post.
Fryatt with a header and Clunan with a shot were both off target as the home defence saw the game out to collect all three points.
Rushden: Heath, Reynolds, Ashton, Collard, Dolman, Rogers, Curtis (Westbrook 57), Farrell, Hicks, Diamond, Lorraine (Bowen 84). Unused subs: Dean, Acquaye, Johnson. Scorer: Lorraine 39
Lynn: Street, Robinson (Jarvis 81), Blake-Tracy, Richards, Fryatt, McAuley, Clunan, Parker (Henderson 60), Gash, Marriott, Mellors-Blair (Hawkins 60). Unused subs: Kerins, Bastock. Booked: Robinson.