Goals from Paddy Madden, Ed Upson and Dan Burn secured the Glovers' fifth straight league victory - and condemned the visitors to only their second league defeat in 16 matches.
Johnson hailed his side after building on Tuesday's win over fellow play-off rivals MK Dons in perfect fashion.
He said: "It was a very important win over a very good side. They are above us in the table and we needed to pull them back towards us.
"It's a great victory and this team seems to be getting better and stronger. The more wins you get on the trot the more confident the lads become in showing no fear, which Ed showed when he struck the ball from 30 yards.
"To get it out of that surface was unbelievable - you'd think he would have needed a sand wedge or something. As soon as he hit it we knew it was on its way.
"The nice thing is that our supporters have now started to believe that we are up there in the mix for the play-offs.
"Every game we go into, I am confident in this group of lads and know they're going to compete and show the desire needed to be in the mix.
"I feel we are on the verge of something special. I've been saying it for a while - so I'm either a witch or a good judge."