His team smashed four goals in 14 minutes before the break as they stretched their unbeaten run to six matches. After David Noble had put Rotherham ahead there was only one team in it. Kari Arnason headed in Ben Pringle's corner three minutes later and skipper Johnny Mullins, who had been loaned out to Oxford earlier in the season, made it three.
Pringle then added a fourth before half-time with a far-post tap-in from Alex Revell's ball across the box to complete an emphatic win for the promotion hopefuls.
Evans said: "It was a great night for us. Goals change games and that's what made it. There was not much in it in the first 15 minutes but once we identified their system, and then put two people wide to stretch them and leave one against one on Michael Duberry, I felt we got on top.
"We got a bit of fortune with the deflected first goal but there was no fortune about the other three goals we ripped them open three times. We're a very attacking side, we've got some very positive players. But it was also a really solid and industrious win.
"In the second half it was about keeping our shape and our discipline. The spine of the team was particularly strong. It's just three more points on the road to where we want to get to. We could have won 4-3 and it wouldn't have mattered, it would have been the same three points. I think our players can get better too."
Oxford boss Chris Wilder took the blame for a change in the way the U's set up and admitted his side let their fans down.
"We had a mad 15 minutes," he said. "We're desperately disappointed, we've let a lot of people down. That's the biggest defeat I've had at home in my time as manager here and it hurts. But Rotherham have got Championship players. And if you give Championship players opportunities, they will punish you.
"I take responsibility for changing the system, but it wasn't the system that caused us to concede the goals we did. Looking at the bigger picture, we've played the three top sides in our league, in my opinion, and won two of the games.
"But we were nowhere near for that mad 15 or 20 minutes. We got a little bit of reaction in the second half. There was a lot of emotion out there with people (fans) leaving before the end, but we have to look at the bigger picture."