North claimed the sixth and final try as Saints brushed Bath aside 43-25 to register their sixth consecutive league win at Franklin's Gardens on Saturday.
The Saints head into 2014 in second place in the Premiership. And rugby director Mallinder believes his side had North's aerial prowess and strike-running threat to thank for galvanising Saturday's pulsating home win.
Northampton were fined £60,000 by Premiership Rugby for releasing North outside the agreed International Rugby Board window for Wales' 30-26 defeat to Australia on November 30.
Mallinder revealed that fine was a "one-off" that will cover the entirety of North's three-year Northampton contract and confirmed the Saints would continue to release North for all Wales matches.
"George was outstanding," said Mallinder. "After that first 10 to 15 minutes he got us going, he got us on the front foot with his carrying, he got us on the front foot with his high balls.
"And just to see his defensive work in the 80th minute to cut them out there, that was excellent too.
"It's taken him a little bit of time, but he showed why he's a world-class player.
"That fine is a one-off, it is a fine and we've accepted that. We'll pay the fine, but we know where we are for the next two-and-a-half years of his contract.
"People hopefully can stop talking about it and we know exactly where we are.
"As a club we've got our fine, and that's for the length of the contract."
North's height and aerial ability exploited Bath's back-three shortcomings, the Wales wing kicking the Saints into gear with visiting full-back Anthony Watson unable to compete.
Bath raced into a 13-0 lead thanks to Kyle Eastmond's try and two penalties and a conversion for George Ford.
But a sin-bin for prop Paul James changed the game. North picked up the pace and Saints plundered three quick tries through Christian Day, George Pisi and Jamie Elliott.
After the break lock Day claimed his second score before Samu Manoa and North finished proceedings.
Bath's second-half tries for Rob Webber and Leroy Houston did little to alter the outcome.
Saints boss Mallinder was delighted with North's match-turning contribution, expecting more of the same in 2014.
He said: "They've got a good back-three with Banahan who is a big lad, but I saw that they were swapping him over a little bit.
"But George North is massive, and he's athletic, so when you kick right and get George up there competing there's not many people who are going to win the ball from there."
Bath head coach Mike Ford admitted Northampton and Saracens were the Premiership's current standout teams.
His side conceded a run of 11-straight victories, their best sequence in a decade, but Ford still believes Bath can fight for a top-four finish this season.
Ford said: "Saints and Saracens, they both got bonus-point wins today, and they are probably up above anyone else in the league at the moment.
"Even with the man in the sin-bin I expected us to defend better, and we didn't.
"They scored three tries more or less on the bounce in that first half.
"To challenge those sides you have to go on a run, which can be done."
Admitting he felt James' yellow card was "harsh", Ford hinted Bath would look to lodge several complaints with the citing commissioner after a high tackle on Anthony Perenise.
"I thought it was harsh, from a first penalty," Ford said of James' sin-binning.
"Anthony got a high tackle, and we'll be looking at a few incidents closely.
"His eye just shut up, that was all, so it wasn't too serious an injury."