The Lions started 2024 at Nethermoor with a defeat.
Kofi Moore won his side a penalty early in the second half but Tom Denton struck the post from the spot.
Dylan Cogill headed home the winner for Gainsborough in the 89th minute.
Commentary courtesy of Guiseley Radio's Colin Robertson and Nik Keefe.
Guiseley 0-1 Gainsborough Trinity | Saturday 6th January 2024 | Nethermoor
Attendance: 629