The match was a feisty affair in which the second quarter proved decisive for Portobello, who went from 2-1 down to claim a 5-3 lead. Bristol caught up to trail 7-6 in the final period but two late goals earned a vital win for Portobello, who owed much to the shooting power of five-goal Antonella Padolecchia.
Team Northumbria completed the Division Two programme with a 100 per cent record, beating West London Penguin 14-11. Tom Dean scored five for the London team.
Caledonia hammered six goals without reply in the third quarter to defeat Sutton & Cheam 14-9. Alistair Campbell was on the mark with five goals for the Scots. Both these teams have already booked Championship 1 places.