The home side came from behind to halt a run of five successive defeats and give Knill his first win since taking charge at Glanford Park before last week's loss at Norwich City.
"This was a massive win for us. After last week's 6-0 defeat at Norwich the first thing I wanted from my team was a performance," he said.
"I wanted to see them more like the Scunthorpe teams I have always known, full of energy and making life difficult for the opposition.
"I have to confess I thought `here we go again' when Rangers opened the scoring. But it shows great character from my team that we came back in to the game and beat the team that has been the best in our league all season.
"We are still in a difficult position and we've got a big match coming up against Reading on Tuesday night where we need another big performance."
The Rangers manager Neil Warnock, a former Iron player, felt the result was fair.
"We got an early goal and if we had got a second I am sure it would have killed Scunthorpe off, we had the chances but we failed to take them," he said.
"I still felt quite confident at half-time but it was Scunthorpe who got an early goal just after the interval and that gave them momentum.
"The goals we gave away were poor, we looked more like a raggy-arsed Rovers. I have no complaints about the result, we got what we deserved.
Source: PA