The Pitmen lifted the Plate on try-count, and it took George’s effort in the 79th minute to get them over the line.
Steffan Castle’s final-quarter heroics looked set to give Ystalyfera the victory.
The full-back kicked a 69th minute drop-goal and a 71st minute penalty to hoist his team into a 16-11 lead.
But Penallta had the last laugh and banished the demons of last season’s heartbreak to secure the win.
Ystalyfera went down to 14 men in the first half after Jesse Patton was red carded by referee Jason Morris for an apparent headbutt.
Penallta have enjoyed plenty of recent success at the home of Welsh rugby after winning the Plate in 2012 and reaching the 2016 final in the same competition.
The rain drizzled down at kick-off which, combined with nerves, made for a scrappy, error-strewn opening.
Penallta went ahead with Bridgend Ravens regular Joseph Scrivens kicking two penalties in quick succession.
Scrivens’ father Richard played a major role in the Pitmen’s 2001 Brewers Cup victory, scoring 26 points against Beaufort – a points record he held for several years.
But Castle, who was the semi-final hero for Ystalyfera kicking a drop-goal in the dying moments to pip Abercarn 24-22, put the men in black on the board with a penalty midway through the first half.
Penallta scored the first try with Corey Tucker benefiting from an awkward bounce to scurry away in the corner.
But the game soon had its first drama after a moment of madness from flanker Patton who saw red for an off the ball headbutt.
Penallta could not capitalise on their man-advantage before the break and struggled to take a grip on things early in the second half.
Their opponents had a try ruled out by the TMO after captain Steffan Jones spilled the ball on the try line.
But that did not matter as a penalty try at the scrum minutes later saw them move within a point and the two teams were even again following prop Matthew Angel’s sin bin.
Penallta came knocking once more and Ystalyfera fell to 13 men after Jonathan Williams saw yellow for an infringement at the breakdown.
The Pitmen could not make the most of the extra man as Fera held firm.
Fears of a repeat of last season’s heartbreak were creeping in for the Blue and Yellows.
And Castle kept cool to bring back those demons, slotting a drop goal to hoist his team ahead by two points.
The full-back was on hand again to slot a penalty from 35 yards minutes later to swing the pendulum strongly into his team’s favour.
Penallta were not finished there, though and came marching back up the other end.
And the pressure paid off when replacement George dived in the corner to tie the game at 16-16.
Scrivens skewed the conversion, but it did not matter as the Pitmen won by virtue of scoring more tries than their opposition.
