Manchester held the upper hand in the early stages, building a 3-1 advantage midway through the second period. But Invicta quickly levelled and, briefly, went 6-5 up in the third.
A tense finale was guaranteed when the match stood at 6-6 with five minutes left. It was then that Invicta struck a vital double blow, scoring twice in little over a minute - by GB Olympians Sean King and Jack Waller - to claim both points.
Cheltenham boosted their Super 5s prospects with a 10-8 defeat of Sheffield, including five goals by Jack Collier. But it's Solihull, now the only undefeated team, who go into the final qualification weekend as top side in the division.
Photo (Trevor Hyde): Invicta goalkeeper Ben Alcorn in action at Luton.