The 10.14 (74) to 8.15 (63) scoreline was is the first time the Power had lost to Hawthorn at the MCG since round 20, 2000.
The game was error-riddled from the start, with plenty of turnovers early - 21 in the first 16 minutes.
The visitors' goalkicking was atrocious - they had 10 behinds and an out-on-the-full to their credit before their second goal late in the second term - and the Hawks got out to a 33-point lead just before that goal.
But Port Adelaide were clearly the better team in the third and through the first part of the last, kicking seven of eight goals, before the Hawks steadied with a couple, including one to Jarryd Roughead, who was again very quiet.
Travis Boak led the way for the visitors, with 14 contested possessions and 11 tackles.
Jacob Surjan wasn't in the top possession getters but was hard at it and used it well when he had it, including a long entry into the 50 which gave Jason Davenport his second goal.
Steven Salopek was another who didn't have a huge amount of ball but used it well, while Tom Logan was hard and tough all day.
Port coach Mark Williams was happy with the endeavour, but admitted his side wasn't good enough in the end.
"It was a pretty competitive effort from our side," Williams said.
"In the first half we had lots of opportunities - I think it was 12 shots to 14 and we only had two goals. We missed some pretty basic shots, snapshots from the goal-square.
"So that made it no scoreboard pressure from us at all, so it made it very difficult for us to dictate too much when it comes to the tactics of the game."
Winning coach Alastair Clarkson trotted out the old 'winning footy is good footy' line, but he admitted it hadn't been pretty in recent times.
“As I said last week when we got the points too, we can’t afford to be too greedy - just get the points and move on," Clarkson said after the game.
"We need to play better footy than what we did today but full credit to Port, we knew they’d bounce back pretty strongly - they obviously would’ve been pretty disappointed with their effort last week on their home ground, losing to the Tigers.
"We knew we had to play some of our best footy to get across the line and we set the game up in the first half then they came at us pretty strongly.
"They got in front and we were really pleased that we showed enough character to get ourselves back into the game and sneak away with a two-point victory."
Luke Hodge, despite horrible kicking for goal with 1.5, and Brad Sewell were terrific for the Hawks. Youngster Ben Stratton continued his good form across half-back.
Shaun Burgoyne was almost invisible for the first three terms against his old side but bobbed up in the last with eight disposals to finish with 14 for the match.
Hawthorn 2.4 7.7 8.9 10.14 (74)
Port Adelaide 0.5 2.10 5.13 8.15 (63)
GOALS
Hawthorn: Ladson 2, Whitecross 2, Osborne 2, Young, Hodge, Rioli, Roughead
Port Adelaide: Davenport 2, Ebert 2, Salopek, Stewart, Logan, Thomas
BEST
Hawthorn: Hodge, Sewell, Guerra, Lewis, Stratton, Osborne
Port Adelaide: Boak, Pearce, K. Cornes, Surjan, Salopek, Brogan
INJURIES
Hawthorn: Young (thigh)
Port Adelaide: Stewart (ankle)
Reports: Nil
Umpires: Rosebury, Ryan, Kamolins
Official crowd: 21,287 at MCG
