Tredrea again was the jewel in Port's forward lines as he racked up 17 kicks, four handpasses and 11 marks - and kicked 4.2 and had a hand (or foot) in other goals as the Power amassed 25 scoring shots (12.13) to the Crows' 15 (9.6).
This match had the usual fierce opening associated with showdowns but did not always produce the sustained quality and competitiveness of many of the previous 15, due partly, perhaps, to Port always seeming to be in control or able to lift another notch when challenged.
Josh Carr, Peter Burgoyne and Roger James directed much of the midfield work, Matthew Bishop stood out in an aggressive defence, in which Chad Cornes forced himself into the game after a slower-than-usual start (against Ian Perrie), and, generally, most players could claim to have made some worthwhile contributions.
Port coach Mark Williams was satisfied enough with the win, but with reservations about the overall effort.
"We're pleased to beat the Crows every time we play them," he said. "I didn't think we played particularly well, especially in the second half.
"But to the players' credit, we kept grinding away. Maybe a few of them just switched off and looked a little bit more towards next week than finishing off this game, which I was disappointed about.
"We'll have to play a hell of a lot better (against Geelong in a qualifying final at AAMI Stadium next Sunday) than we did today because today's effort wasn't good enough.
"It will be an important week on the track for a few people if they want to get in the side. Adam Kingsley (adductor) will be back, that's for sure."
Williams described the players' mood after the match as 'pretty matter of fact'.
"We certainly want to celebrate that it's an important game to win but no one's over the top," he said. "We moved on very quickly from the warm-downs to what I had to say to them, and they're looking at next week.
"Finals games are 50-50 and that's really been proven to us over the last few years. It's easy to say we're on top but we've been on top for probably only one or two weeks of the year.
"In South Australia, there are two teams to choose and we're happy to have broken even with the Crows this year. To establish ourselves as the No. 1 team in SA, we have to do something in the next couple of weeks.
"The result of this game is always important but the fact is next week is the most important game for us."
ADELAIDE: 2.1, 4.2, 8.5, 9.6 (60)
PORT ADELAIDE: 5.2, 8.6, 11.10, 12.13 (85)
Goals: Adelaide: Biglands 2, Edwards 2, Stenglein, Goodwin, Perrie, McLeod, Ladhams
Port Adelaide: Tredrea 4, Wanganeen 2, Thurstans 2, Cassisi, Pickett, Lade, James
Best: Adelaide: Edwards, Goodwin, Biglands, McLeod, Perrie, Ricciuto
Port Adelaide: Tredrea, Carr, P Burgoyne, James, C Cornes, James
Injuries: Adelaide: Clarke (eye), Reilly (ankle), Hentschel (ankle)
Port Adelaide: Nil
Changes: Adelaide: Welsh (calf) replaced in selected side by Begley
Port Adelaide: Kingsley (adductor) replaced in selected side by Dew
Reports: Adelaide: Goodwin reported by umpire Roseworthy for allegedly tripping James
Umpires: Kennedy, Rosebury, Meredith
Crowd: 45,473 at AAMI Stadium
