It was Sheffield's second win of the weekend - and Invicta's second single-goal defeat.
Invicta dominated the early stages, leading 4-1 after two periods and 5-1 after three. Then the game changed completed as Joe Abbott (2), Chris Armstrong, Connor Carpenter and Finlay Parnell fired in goals that gave Sheffield a 6-5 lead. Further scores by Elliot Kelly and Ben Stephenson completed a fine Sheffield performance.
Manchester also won for the second time - 15-3 against Sutton & Cheam. Solihull drew 9-9 with Polytechnic, rescuing a point just three seconds from the end thanks to Ryan Padbury's fourth goal.
Cheltenham were involved in another storming match at the end of day two. They drew 10-10 with Lancaster, whose hero was goalkeeper Marc Robinson. He achieved a rare hat-trick early in the game - three penalty saves - which were to prove crucial later on.
Only teams with 100 per cent records after the first matches in Division 2 are the two Scottish sides. Caledonia outplayed Exeter 19-8 while Portobello beat Welsh Wanderers 14-8, including hat-tricks for Luca Pollock, Ed Grundy and Ben Scott.
In men's Division 5, leaders Chester dropped a point for the first time in a 4-4 draw with Newport. Invicta Marlins beat Watford Saxons 14-7.
Exeter notched another big win in women's Division 3, Ella-Louise Jones contributing nine in a 24-3 demolition of Manchester Comets. Cheltenham are top after defeating Watford 11-3.
Photo (Trevor Hyde): Ella-Louise, right, in action against Manchester.