The Millers fell behind to an early Joel Grant strike but Daniel Nardiello's second-half double had them on course to move up to fourth in the League Two table, before Doherty's 81st-minute header.
But Evans believes his side's attitude bodes well for the run-in, with Rotherham three points off an automatic promotion place with nine games to play.
"I thought we were out the game in the first 20 minutes, we were poor and it looked as if we were still on the coach to be honest but we were delighted there was only a goal in it," said Evans.
"We got two great individuals goals from Nardiello and then we are undone by a set-play. I told (Andy) Warrington he heads that from four yards out and he should be clearing him out but he knows that.
"We never stopped and it is a mentality of teams who are successful, they just never stop. They took the strong words I had for them at half-time and they reacted in the right way.
"We have to get ready for another tough one at Cheltenham and it is another big game. All we can do is go about our business and try and win football matches."