Despite being hit with a number of absentees due to the international break, Saints edged out London Irish 14-19 at the Madejski Stadium which had temporarily moved them to the top of the Aviva Premiership.
"We made heavy work of it, but a win is a win," Mallinder, Saints director of rugby, told reporters. "Irish are a tough challenge here, so I have to be pleased.
"We have lost a lot of our players to England but we are managing to get by fine. It's important we maintain our momentum and this will help."
James Wilson scored Saints' only try of the match.