Three first-half tries took them clear but the visitors remained in touch with a battling second forty, during which both sides crossed twice.
Crunching work by Teimana Harrison from the base was matched by Danny Hobbs who blasted his way through a Gloucester second row for the game's first try and a second through fellow prop Danny Herriott was a show of combined forward force.
Tom Stephenson powered through the Gloucester backline to tee up Tom Collins just moments later and the centre then shrugged off several tacklers to register the first score after the break.
The fifth came through a fine finish from Howard Packman but the visitors hit back with two tries of their own through Mirab Sharikadze and Steph Reynolds, the second of which was the evening's final score.
11mins SAINTS Try Hobbs Con Olver 7-0
20mins GLOUCS Miss pen Thomas
27mins SAINTS Try Herriott 12-0
29mins SAINTS Try Collins 17-0
35mins SAINTS Miss pen Hooley
HALF-TIME SAINTS 17 GLOUCS 0
42mins SAINTS Try Stephenson Con Olver 24-0
55mins SAINTS Try Packman 29-0
57mins GLOUCS Try Sharikadze 29-5
60mins GLOUCS Try Reynolds 29-10
FULL-TIME SAINTS 29 GLOUCS 10