TRAVIS Boak concedes Port Adelaide's rise from also-rans to top-four contenders has surpassed his loftiest expectations.

The Power skipper's faith that the club could turn its on-field fortunes around was a key reason in his decision to reject offers from several Victorian-based clubs and sign a four-year contract to remain in South Australia.

He held that view in 2012 when Geelong, among others, sought his services after the Power finished 14th with just five wins.

But the speed with which Port Adelaide has risen to the top was not something not even he could fathom.

Port Adelaide's 40-point win over Geelong on Sunday catapulted the Power to the top of the AFL ladder after six rounds.

"I probably didn't think it was going to happen this quick," Boak told Fox Footy's On The Couch.

"I knew it was going to happen eventually. A couple of years ago, when I was going through the contract stuff, I knew we had the right group to go forward."

Rightly, coach Ken Hinkley, strength and conditioning coach Darren Burgess and president David Koch have received plaudits for their role in the Power's regeneration.

But Boak believes the Power players' willingness to improve and stand up to the challenges the club's coaching staff have thrown at them also needs to be lauded.

The Power captain has driven the ruthless attitude his club has displayed this season, while his form has led him to the top tier of midfielders alongside Gary Ablett, Scott Pendlebury and Joel Selwood.

Boak is sure the elevation in his footy has come from a more selfless mindset in the way he approaches the game.

"The biggest thing for me was the captaincy," he said.

"My biggest criticism was just worrying about my game and how I could improve as a player.

"But that sort of got into my head a little bit and I wasn't performing how I wanted to be.

"Once I got the captaincy it was all about leading the team and how I can do that the best way I can."