Our young Reds were made to work hard for the three points, with Obi having hit the post twice inside the opening 45 minutes at the City Football Academy.
But Gabriel opened the scoring with a well-taken finish midway through the second half, before Obi doubled our advantage with a brilliant effort soon after.
Tyrone Samba pulled a goal back for the hosts inside the final five minutes, but Jim Thwaites rifled in a free-kick to make sure of another league success for United.
FIRST HALF
On a bitterly cold morning at City's footballing headquarters, Godwill Kukonki set the tempo early on with his driving runs down the left flank, teeing up Gabriel for his first strike of the game.