Northampton boss Aidy Boothroyd was full of praise for his players after they saw off much-fancied Rotherham at Sixfields.
Alex Nicholls grabbed the late winner to earn Cobblers all three points in a 2-1 success.
"Our performance in the first 35 minutes was as good as any we've produced since I've been here," enthused Boothroyd.
"I thought we were well worth our win tonight. We were fantastic, the work ethic, commitment and our passing was excellent, and we outplayed them in the middle of the park.
"The only thing I was disappointed about was that we didn't score three or four goals because we created some great chances.
"But Rotherham are a very good side and I knew they would come back at us. They were stronger than us for long periods in the second half but if teams want to try and dominate us we've got quick players who can catch them on the break."
Millers boss Steve Evans said: "That was daylight robbery. For an hour there was only one team dominating and that was Rotherham United.
"Their keeper has made some key saves and at no stage did I think they were going to score. We were trying to force the winner at the end because we want promotion but we've got caught on the break and that was sloppy.
"It's a bitter blow to swallow but we have to take it on the chin. If Northampton are the benchmark then we'll be right up with them at the end of the season because we're better than them. They can celebrate, we will commiserate but we will bounce back."