PORT Adelaide coach Mark Williams has credited his team's newfound belief for its come-from-behind win over West Coast in Warren Tredrea's 250th match.

The Power started well to lead by as much as 27 points 10 minutes into the second quarter, before West Coast looked to have Port Adelaide on the ropes with a 13-point lead at the final change.

Williams was impressed with his team's inspired final quarter and delighted to now be two from two this season.

"That was one of the great games. We totally just hung on and hung on, but the belief of the boys and effort they showed in the last quarter should be something they are proud of. I was very concerned I have to say," Williams said.

"We changed a few things up and I can't say that they always work, but they certainly did this time and that was great. The players had a great belief and confidence in each other and they went out and delivered."

Jason Davenport was the hero with four goals in the last quarter. Williams was pleased to see him stick to his guns, as he was with Dean Brogan and Justin Westhoff in the ruck, and his defence led by Troy Chaplin.

"Jason Davenport had a pretty non-eventful game until the last quarter and kept missing goals when he had great opportunities that he didn't take. To keep the confidence in himself to be able to finish off like that was terrific," he said.

"Westhoff and Brogan were outstanding given the quality of the opposition and they kept going. In the last quarter they were very significant for us. Our backs were terrific and they won so many one-on-one contests."

Williams flagged the return of Robbie Gray and possibly David Rodan and Daniel Motlop for next Saturday's match against the Brisbane Lions at AAMI Stadium.