Jim Mallinder admitted Saints were far from at their flowing best in the 18-0 win against Newcastle Falcons.
Second-half scores from James Wilson and Luther Burrell secured the success but Mallinder’s men were made to work hard by a determined Falcons team.
The plucky away side limited Saints to a 6-0 half-time lead as Stephen Myler punished Falcons for the sin-binning of lock Carlo del Fava 10 minutes before the break.
But Dean Richards’ men conceded two quickfire tries without reply, giving Northampton their sixth win in succession.
And Malinder, who had seen his side score 23 tries in their previous five home games, said: “We knew it was going to be hard work breaking down Newcastle because that’s the way they play. They’ve played like it all season.
“They’ve got a big, heavy pack and they defend very well and we weren’t quite as fluent as we’d have liked.
“You’ve got to give a lot of credit to Newcastle for the way they defended, the way they shoved numbers into the breakdown and slowed everything down.
“We won 18-0, we stopped them from scoring, we’d have loved to have gone on and score four tries but sometimes that doesn’t happen and we won the game.
“Our set piece was good, our scrum was good and I don’t think we got just reward in that.
“We needed to take our opportunities. We weren’t quite as cohesive as we have been this season.”