Manchester had little difficulty booking their place - they defeated Welsh Wanderers 20-5.
Penguin then faced great rivals Polytechnic. The sides' two meetings in the Super 5s had both required penalty shoot-out deciders - one win apiece - and this thriller could easily have gone the same way.
Early in the third period, it was 4-4, which progressed to 8-8 at the start of the last.
Penguin then struck two crucial blows, smart finishes by Charles Kingsmill snatching a 10-8 lead. This improved to 12-9 3.07 from the end as Albie Duffy scored. Back came Poly, scoring through Matt Klingenberg (2.34) and then Caleb Simpson, 52 seconds from the end, to cut the deficit to a single goal.
At the restart, Poly somehow regained possession and called a time-out - 26 seconds remaining! They couldn't fashion a goal, so Penguin celebrated a thrilling 12-11 win.