Mallinder also praised scrum-half Lee Dickson and Ryan Lamb after the victory.
He said: "It was a good performance today. We've been building towards that and we've had some good halves of rugby but I think today we were all round a good team in terms of our tempo and our attacking play."
In particular, he identified some superb defence, as his side resisted Quins while a man short in the second half.
"Defensively we shut them up and stopped them playing, which of course they are good at, so we're very pleased," he said.
Mallinder reserved special praise for his halves pairing of Dickson and Ryan Lamb, the latter kicking 13 points and providing a sublime pass for Roger Wilson to score the side's second try.
"Ryan was excellent. His decision making was outstanding; he's maturing rapidly and playing some good rugby.
"Lee's been very good for us and is actually getting better. He's been good for us for the last two or three years and I have described him as being the heartbeat of Northampton.
"We want to play a high tempo game, we want to get the ball away, and when you have players like Ryan Lamb as well and you have good runners running good angles that's how we want the game to be played."
Harlequins director of rugby Conor O'Shea, contemplating his side's second defeat of the season, admitted they had been out-muscled by Saints.
"They were just more physical than we were and they won the contact and collision area. They got momentum," he said.
"If you come here and don't get momentum then you're going to be in for a tough night. They were outstanding tonight and we weren't.
"For the first time this season there was an 80 minutes where we haven't actually performed, but that happens."
After a good start, Quins were undone during a crucial 10 minutes when Nick Easter was in the sin bin.
Saints shot out into an 11 point lead, which became 14 points just after Easter returned.
"We started the game pretty well but we didn't get any score and we offloaded when we shouldn't have, and we coughed the ball up," said O'Shea.
"They got the lead and gave the crowd and themselves a bit of a buffer to relax and play."
Gilbert has released a new line of rugby cleats. The Gilbert Virtuo 8S is part of the exciting new product. Check it out.
The entire All Blacks apparel line has been updated for 2013/14. Check out the New Zealand All Blacks polo.
The Nike Tiempo is a solid rugby cleat and one of few styles still made from full-grain natural leather.
The Gilbert Blitz 8S rugby cleat is a great cleat at a great price of $69.99. Get a new pair of cleats today.
A cool looking all black rugby cleat with the high performance adidas is known for. Get in the Gear!
Wear the crest of the British and Irish Lions on your t-shirt. A great look for the summer.
The All Blacks Performance t-shirt is black with hints of blue from the training jersey. Very Cool.
The New Zealand All Blacks training jersey for 2013/14. Get in the Gear!
The USA Rugby Pro Alternate rugby jersey is perfect for any fan of the Eagles. Get yours to wear during the summer Test matches.
The NEW All Blacks 2013/14 jersey has arrived at World Rugby Shop. Dare to wear the colors of the All Blacks.