Victory lifted Dale to the top of League Two, but it was a far from routine win for the home side.
They were behind just 40 seconds into the game when Luke Norris smashed home a glorious 25-yard strike.
George Donnelly then netted the winner two minutes later to make it five successive wins on home turf, but Hill felt victory had been achieved in spite of a below par performance.
"In a way we have got away with being somewhat below our best," he said. "We have good technicians in the side and when opportunities present themselves then we can take advantage.
"I am pleased with the result considering we were only playing at 70 per cent of our capability, but I also have to give the opposition credit for that.
"It was a world class opening goal from them and it encouraged them to set their stall out to frustrate us. They were resolute and disciplined and I thought we were going to be in for a very long night, and at times it felt like that.
"We got back into the game but I felt we could have done something about their second goal - in fact I know we could have. But we eventually got there and it has worked for on this occasion."
Cobblers boss Aidy Boothroyd said the visitors' dressing room was a sombre place to be.
"We have a very deflated dressing room after that," he said. "It's all about very fine margins between winning and losing and for long periods you wouldn't have known which side was at the top of the league.
"But I said to the lads afterwards that the reason they are top of the league is because they keep going to the very end and we make silly mistakes.
"We conceded a silly free kick, they score and the whole crowd is lifted and they get the momentum. The third goal was a poor one from our point of view.
"The game looked finished at 2-1 and it's difficult to take a defeat like that. But they are on a great run at the minute and things are going for them.
"We have to keep calm, show bloody-mindedness and keep going because I know that we will start winning games. There were many encouraging signs but they are difficult to see at the minute because we have lost."