Ray Grant returned from injury to turn in a solid performance in Trinity’s defence and they won with goals from Dave Le Roux and former professional Ashley Dodd sandwiched by Darren Swanson’s penalty kick.
St Peter stretched their unbeaten league run to eight games after returning with maximum points from St Brelade.
Jon Trigg’s side had an excellent start with three goals in the opening 17 minutes, Vitor dos Santos playing in Marco Vieira for the opening two goals before grabbing the third himself with a fine strike.
Chris Hamon and substitutes Scott Walsh and junior Ryan Le Cornu took St Peter’s total to six before Jason Reynolds nodded home a late consolation.
Grouville consolidated fourth position after completing a league double, without conceding a goal, against St Paul’s.
Island squad player Chris Carter scored and made one goal in Grouville’s 4-0 victory on his début.
St Paul’s squandered a couple of good chances too while Grouville took theirs twice through Alex Jefferies and substitute Toni Cardoso’s twelfth of the season.
Referee Ray Sutcliffe called off Jersey Wanderers’ home match against Rozel Rovers at the Hockey Club because of a waterlogged surface.