The half-time scoreline read just 3-0 in Saints' favour before five tries in the last 18 minutes and 17 further points from the boot of fly-half Stephen Myler gave the final outcome a healthy pre-Christmas glow.
But despite the nervy nature of the opening half, Mallinder insisted he and his players never saw the need to panic as they looked to avenge a 41-22 defeat to the same opposition last weekend.
"We said not to get frustrated and to keep defending the way we were doing when we spoke at half time," said Mallinder, who led Saints to last season's Heineken Cup Final in Cardiff.
"I think we could have scored a couple of tries in the first half. We got close to their line a few times but didn't quite finish them off. I was always confident we were in control of the game and that's what we talked about at half time.
"We wanted to look for a little more accuracy in our clear out, look to get some quicker ball and turn them if the opportunity was there. We knew we were going to be playing with a little bit of a breeze and a bit of a slope in the second half and we wanted to keep their pack moving around and then the gaps would come.
"It was a good second-half showing and that was all about getting good ball on the front foot. A lot of credit must go to the subs. Sometimes people say you make subs just for the sake of it, but what you want is for to those players to come on and make an impact. Our forwards and the two young centres who came on all made an impact.
"Today was all about us producing a good performance and building on last week's attacking game and we did exactly that with our discipline and defence.
"The final scoreline may have flattered us a bit but you've got to do the hard work before that. It was the three penalties just after half-time that did the damage: suddenly the opposition knows they've got to over play if they want to win."
Saints now sit third in Pool 1 but require a favour from Castres if they are to have any hope of catching runaway leaders Munster who are eight points clear of last season's beaten finalists.
Finishing second in the group remains a real possibility, however, with a best runners up spot and therefore a place in the Heineken or Amlin Challenge Cup quarter-finals now on the cards.
And while things didn't go to plan in their opening three pool games, Mallinder insists his side will keep plugging away while qualification of some sorts is still mathematically within their grasp.
"We just have to keep going," added Mallinder.
"All we could do today is go out and get a bonus-point win and we've managed that.
"We've got two tough games now when the tournament comes back. We're away at the Scarlets and then home to Munster.
"It gives us a chance of going through to the Amlin Challenge Cup quarter finals. I think we'll need a couple of good wins, which of course won't be easy.
"It's not impossible but we'll approach that when we get there."