Jim Mallinder praised George North after the Wales back galvanised Northampton to a 43-25 Aviva Premiership victory over Bath.
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.
"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.
"They (Bath) have 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.
"Saints and Saracens, they both got bonus-point wins today, and they are probably up above anyone else in the league at the moment," he said.
"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."