Player-manager Keith Rudd swept the Linnets into a sixth minute lead when he pounced on a mistake by goalkeeper Paul Frankish.
There should not have been any danger when Frankish went up unchallenged to reach Jim Kabia's flighted centre from the right.
But when the ball slipped through the keeper's fingers he turned to watch Rudd snapping up the chance to score into an empty net. It was Rudd's first league goal at The Walks since Lynn joined the NPL, although he has scored 13 on other grounds.
Conditions for the players - and especially both goalkeepers - were extremely difficult. After heavy recent rain it was surprising that the game went on at all, with large pools of water glistening under the floodlights.
After this early breakthrough, the Linnets tended to sit back and allow Gainsborough a lot of possession but the visitors still did not make much impression.
Colin Foster looked calm in defence for the Linnets and in mid-fielder Chris Watts they had the player of the match as he buzzed effectively.
Early in the second half Gainsborough had a rare chance which was wasted as Trenton Wiggan shot too close to Andy Claxton.
Lynn finished strongly and Paul Bartlett sent in a stinging shot which Frankish turned away. The winger had the final say, however, when he deflected a 20-yard shot from Craig Thompson which beat the despairing drive of the wrong-footed Frankish.
|Lynn: Claxton, McJannet, Bircumshaw, Foster, Wiles, Easthall, Thompson, Watts, Bartlett, Rudd, Kabia. Sub: Howard.
Gainsborough: Frankish, Hull, Jones, Lodge, Bennyworth, T Thompson, Snee, Wignall, Wiggan, J Thompson (sub Cowan 75 mins), Brolly.
Referee: J Jones (Doncaster). Attendance: 201.