Warriors have now gone eight games unbeaten in Europe and are potentially just 80 minutes from Heineken Cup rugby next season.
And Griffiths was full of praise for the team and backroom staff who have turned around a season that started in difficult fashion.
"After all the trials and tribulations we have gone through this season we are now just 80 minutes from next year's Heineken Cup, it is an amazing turnaround," said Griffiths.
"After the start we had this season and coming close in so many games this is real reward, we stuck in there and everyone worked hard.
"We wanted to change the style of play here and as it showed tonight it was good to watch. When we needed to slow it down we could, but when we wanted to spread it we could. We kept the opposition thinking at all times
"We don't mind who we get in the final, we dust ourselves down and concentrate on the league now."
Griffiths also heaped particular praise on the Worcester defence who stopped a Newcastle side crammed full of international flair in the back division.
And not even a powercut in the local area - that plunged Sixways into darkness for ten minutes before power was restored - could halt the men in gold and blue.
"We tried to play bright rugby - despite the stoppages," joked Griffiths.
"Seriously though, it was an awesome game; they are a good side with a potent backline. But when we got in the right areas we capitalised on it.
"I have to pay tribute to our defence because they really moved the ball around. They have some real ball players in Wilkinson, Flood and Tait.
"It was a good game to watch, but nervy when they came back in the second half. It was also nice to get a win after losing up at Newcastle, we put the record straight and no one can argue with that result. They had a good slice of the game but they could not cross the line."