Croydon led 6-3 at the halfway stage and still retained a three-goal advantage at 9-6 early in the final period. Then exclusions proved costly for Croydon as Joao Martins and Ben Curtis cut the lead to 9-8 and Martins struck again with a minute remaining on the clock.
Penguin had no difficulty easing through their first match, beating Southampton 16-9, including five goals from Claudio Bagnoli and four from Drago Ungureanu. Later, Ungureanu helped himself to seven in a 17-10 win against Croydon.
At Liverpool, also in men's Championship 2, Joe Jenkins-Delf (4), Lewis Gilmour (3) and Dan Laxton (3) were among the scorers in Welsh Wanderers' 17-10 defeat of Castleford.
Portobello beat Cambridge 13-11, scoring five times in a decisive third period after the sides were locked at 5-5 after two.
Men's Championship 1 got off to an exciting start as Invicta and Sutton & Cheam shared the points in a 9-9 draw at Haberdashers. Invicta were never ahead until they went to 8-7, then 9-8, in the final quarter. Toby Hook's third goal then provided a Sutton equaliser.