Warrington palmed away two Lee Mansell first-half strikes before Rotherham took control in the second period.
Lee Frecklington's 20-yard strike was fumbled in by home keeper Michael Poke before Alex Revell raced away to make it 2-0 in the 59th minute and although Billy Bodin won and converted a stoppage-time penalty, when tumbled by Mark Bradley, Rotherham's reply was immediate.
Courtney Cameron crossed from the right to give fellow sub Kayode Odejayi a simple tap-in.
"The goalkeeper made two or three saves at important times for us and at the same time we scored three but could have scored six or seven," said Evans.
"It was a hard-fought win, the pitch was never conducive to good football. As you can see it's not the best in the league but you have to come here and you have to work hard.
"It was a bit too much end-to-end for me when we were 2-0 up but over the piece I have got to be delighted because it is a hard place to come and win.
"We didn't play well first half but I thought Andy Warrington, Claude Davis and Johnny Mullins were immense in the first half. I don't think they had much to do in the second half, maybe Warrington had one save to make.
"I think we might have been unfortunate with the penalty. I will look at the DVD because our lads weren't happy and I don't think the Torquay lads claimed it.
"But, anyway, we had a great reaction. Courtney's piece of magic gives Kayode a tap-in. It was a good win for us."