The midfield man also pointed to Gers keeping another clean sheet – although he revealed the manager had some stern words to his players at full-time about keeping up their high standards.
Jack explained: "We are buzzing with the win. It's another clean sheet and another three points to take us to where we want to be, so overall, we are happy with the result, but in the performance, we always strive to get better.
"The manager said after the game that it is another big three points and another clean sheet, but he is never going to be off us - he is always going to be on us and he wants us to give him more.
"Jon makes a great save, and throughout the season, we are going to need that. We are going to need players to step up and Greegsy has done it time after time and tonight, Jon did it for us."
Gers’ scored three fantastic goals tonight – two set-pieces and a cracking team goal, with Jack continuing: "Since pre-season, the gaffer has said he wants us to build from the back and get in positions to play it out.
"So the second goal is excellent and then Joe [Aribo] gets his goal with the header from the set-play - TC [Tom Culshaw] is working tirelessly on the set-play side of things every day in training, so it was good to see that come off.
"But I am delighted with the three points and we move onto Saturday now.
"Borna's was a great set-play and you see him working on that in training as well. Overall we are pleased as it is another victory which takes us where we want to be and we have another tough one on Sunday."