And the vice-captain admitted the players could hear the travelling support roaring them over the line.
Pennell said: "The support was amazing. We could hear them getting behind us despite being outnumbered by the home support.
"Given our position in the league and without a win before Newcastle, to have that sort of support behind you means an awful lot.
"We can't thank them enough for making the effort and travelling all the way to Newcastle to support us."
The full-back, who kicked two penalties in the match, praised the impact of the players that came off the bench to help Warriors secure victory.
He continued: "There wasn't a stage in the match that I felt we would lose or concede any tries. Defensively we were solid.
"We had to make a couple of late tackles but that's the job. Other guys were chucking themselves around at key moments and getting turnovers like Paul Andrew and Ed Shervington.
"Those last 20 minutes were a testament to the guys that came off the bench and the impact that they made."
And Pennell insists Warriors must now give everything they've got in the final four games, if they are to remain in the Aviva Premiership next season.
He added: "We have to go into every game believing we can win. There are only four games left and they have to be four 80 minutes of absolutely everything we've got.
"If we do that then we can look ourselves in the mirror at the end of the season.
"After the final whistle goes against Gloucester on the last day, we need to know that we've given our all and I reckon if we do that, we will be playing Premiership Rugby again next season."