Andy Glover was the hero as he came back to haunt his old club as FA Cup holders St Mary’s clinched a place in the quarter-finals on Saturday.
Glover scored a hat-trick, including a last-gasp winner, to seal a 3-2 victory over St John’s at the Bowl.
Extra-time looked on the cards when St John’s twice came from behind with two well-taken Louis Morris goals.
However, Glover struck late on to seal a win.
In the only other game to survive the weather, Second Division Pulrose shocked top flight Castletown.
They won 6-5 in a dramatic penalty shoot-out after a 1-1 draw.
Kieran Iveagh had put Castletown ahead before Town were reduced to 10 men when Karl Stanniford was dismissed after 20 minutes.
Pulrose used that to their advantage and fought back with Aaron Raby equalising.
With no further goals in normal or extra-time, Pulrose triumphed on spot kicks - Nathan Yates netting the sudden-death winner - to clinch their place in the last eight.