Cobblers boss Jimmy Floyd Hasselbaink admitted he didn't expect such a substandard, out-of-sorts performance from his side on Saturday when he blamed their 3-0 to defeat to Rotherham United on too many 'individual mistakes'.
On the back of three straight draws, hopes were high that Town could get something out of their clash with the high-flying Millers, who themselves had lost two successive games, both to teams at the bottom.
But the Cobblers could not make it three in a week, far from it, as they were comprehensively outplayed and deservedly well-beaten in a result that continues their poor recent home record.
Michael Smith's 18th minute goal set United on their way and David Ball's second on the hour-mark ensured there was no way back for Northampton, with Richie Towell adding insult to injury with a fine goal 10 minutes from time.
"I'm very disappointed," said Hasselbaink afterwards. "We didn't anticipate this kind of performance and we expected a lot more, especially after the result last weekend and how we came back with 10 men.
"It comes down to individual mistakes. At the moment, we're giving the opposition too much at home with the amount of mistakes we're making.
"The early goal settled them down and meant they could play with more freedom. They were able to take their time and it made it easier for them.
"At this moment in time, we're not the kind of side who can go a goal behind against this kind of team and then get spells in the game when you're really on top of them.
"We didn't create enough either and we didn't give them enough trouble and that's the disappointing thing because we've worked really hard on getting that right."
The stuttering home form will be the major concern for Hasselbaink, whose side have won just four of their past 16 games at Sixfields and now sit back in the Sky Bet League One relegation zone, only one point above MK Dons.
"We need to find an answer really quickly because we have four more games at home and we really need to try and win them all," he added.
"I don't think we started slowly. They had the ball and they played with the wind with them which put us on the back foot, and that's not excuse.
What they did well was camp us in because we couldn't get out and then when we did get out, we were a little too rushed and that's where we should have been better."