Dew scored two crucial goals and assisted with another in the third quarter in a period of the match that Hardwick hailed as game-turning.
"He kicked two goals and set up Williams. It was probably a game turner, in essence," Hardwick said.
"When he said he was coming back I thought it would be a long shot that he'd play so well, never mind win a premiership. So from his point of view the whole thing has been a Cinderella story. He wouldn't have dreamt this in his wildest dreams."
Hardwick also heaped praise on first-year player and emerging star Cyril Rioli who kicked two goals during the Hawks' 26-point victory over Geelong.
"If he's not a superstar he's well on the way to being one. He's a guy that players love to play with and he has the ability to change games. His tackle and defensive play was just outstanding.
"I thought that in the second quarter he kept us in the game. As far as I could see he was the only guy who was running and creating opportunities. You just can't teach that. It's bred into him. He's going to be a wonderful player for us for a very long time.
"The world's his oyster as far as I'm concerned. He'll probably feature in the top of our best and fairest, that's how important he's been to us."
On a day when Lance "Buddy" Franklin kicked just two majors, Hardwick said the win showed that the forward line was more than a one trick pony.
"Today really showed that. Buddy to his credit really played his role. Everything we asked of him he did. He went up the ground and he played on the wing for a while because we needed some run. He took away the dangerous defender in Scarlett, which opened the door for Mark Williams and Jarryd Roughead."
Having played as a defender for his entire career at Essendon and Port Adelaide, Hardwick said he was proudest of the negating qualities of the forward group of which he is in charge.
"The thing I've been really impressed with is their defensive pressure. The improvement from round one this year to game 25 was outstanding. The amount of pressure they put on the opposition rebounding the ball was terrific.
"They've shown that if you can't tackle you can't play in the Hawthorn forward line. That was the most pleasing thing from my point of view."
