St Paul’s improved their goal difference with a 6-1 hammering of Rozel Rovers at Le Couvent, with Mark Lucas hitting a treble and JP Martyn, Craig Russell, Craig Leitch adding singles.
James O’Haire was on target for Rovers, who slip into the second relegation spot with 13 points.
Unbeaten Trinity kept their impressive campaign on track with a 3-1 win over a battling Jersey Wanderers, who are just above Rozel on goal-difference.
Wanderers, suffering their first defeat in five games, finished with nine men after Stephen Reed and Karl Sutton both picked up two yellow cards, the pair being dismissed in the second half.
Island striker Barry Beaston, Darren Swanson and James Hayward scored for Trinity, with Luke Campbell heading an equaliser for Wanderers – and every goal is important in a division as tight as Division I, at both ends of the table.
Grouville gave their survival hopes, and confidence, a huge boost by smashing pointless Tower for six unanswered goals at La Hague.
Tower still cling on to their divisional status, but it is only mathematics, not sporting reality, that gives them any hope.
Three goals in each half, with a double from Stephen Ross and singles from Luc Le Mire, Peter Hall, John Kiersey and Jason Byrne lifted Grouville up from second-bottom to mid-table, such is the compact nature of the relegation and title fights.
The expected three-point windfall coming Rozel’s way because of a Jersey Scottish fielding a suspended player in a recent match would lift Rovers above Grouville and put Wanderers back in the drop zone.