The Cats superior class eventually told in what was a largely scrappy affair. They won 0.11.6 (72) to 1.6.9 (54).
The first two of Stokes' three fourth-quarter goals came on the back of the game's lone supergoal, when Daniel Motlop's long-range effort had brought Port Adelaide to within one point early in the last quarter.
But that was as close as the Power would get with a clever soccer and then a set shot from Stokes (four goals) giving his team the decisive break.
His third came after Chad Cornes missed a gilt-edged chance to keep the Power breathing when he missed an easy shot from directly in front.
Jimmy Bartel (28 disposals, five tackles) combined toughness with poise in another fine match, while Paul Chapman (25 possessions, one goal) and James Kelly (26, one) were also solid.
Kane Cornes had a game-high 31 touches for the Power, and Josh Carr showed he will be valuable back at Alberton with 26 dispoals. Nathan Krakouer's game at half-back (22 disposals) was also encouraging.
The Cats held a ten-point advantage at the final break after kicking the only two goals in an uneven and error-ridden third quarter.
The first, to Tom Lonergan, was the result of a questionable free kick. The second, though, came from a beautifully executed passage of play that saw the ball in Bartel's capable hands after the Cats swept upfield with pace and precision.
But that was a rare highlight. Port Adelaide, in particular, spurned its opportunities and managed only four behinds for the quarter.
A rash of nine-point attempts late in the term failed to land a supergoal as both teams went searching for a decisive blow ahead of the final quarter.
The first half was also highlighted by poor disposal, but what it lacked in polish it made up for with hardness.
The Power, missing former skipper Warren Tredrea and the Burgoyne brothers, appeared keen to test themselves physically against the Cats and it paid off the in the opening term.
Port Adelaide took it to the 2008 grand finalists and trailed by a solitary point at quarter time.
Stokes opened the game's scoring but Power rookie Thompson answered, using his electrifying speed to run onto a high ball inside 50 and convert for the first of his two goals.
The thumps and bumps continued, but the Power’s hard-nosed approach started to take its toll on the free kick-count.
A high tackle from Josh Carr gifted James Kelly a goal and rookie Danny Meyer was reported for his challenge on Geelong tough nut David Johnson.
First-round draft pick Hamish Hartlett was also a victim of the hot first term when he injured his AC joint in a heavy tackle from fellow South Australian Ryan Gamble.
But the Power’s fierce tackling was finally rewarded late in the term when Danyle Pearce caught Josh Hunt holding the ball and converted the resulting shot on goal to reduce the margin to a point.
Geelong applied the brakes to Port Adelaide in the second term as the home side struggled through the defensive zone.
The Cats pushed all their players forward of centre and the Power were forced into turnovers as they attempted to penetrate the corridor.
The visitors pounced with consecutive goals to youngsters Nathan Djerrkura and Scott Simpson but Thompson's second, and a high mark and finish from the ever mercurial Daniel Motlop, kept Port Adelaide in touch at the main break.
Geelong will face the winner of Sunday's Carlton-Hawthorn clash, while Port Adelaide will take on North Melbourne in a NAB Challenge game.
Port Adelaide 0.2.1 0.5.1 0.5.5 1.6.9 (54)
Geelong 0.2.2 0.5.2 0.7.3 0.11.6 (72)
GOALS
Port Adelaide: Nine-pointers: Motlop Goals: Thompson 2, Motlop, Pearce, Westhoff, Salopek
Geelong: Stokes 4, Kelly, Simpson, Chapman, Kelly, Djerrkura, Lonergan, Bartel, Varcoe
BEST
Port Adelaide: K Cornes, Carr, Krakouer, Carlile, Thurstans, C Cornes
Geelong: Bartel, Stokes, Enright, Chapman, Johnson, Djerrkura
INJURIES
Port Adelaide: Hartlett (AC Joint)
Geelong: Nil
Reports: Danny Meyer (Port Adelaide) reported by umpire Nicholls for bumping or making forceful contact with the front of David Johnson (Geelong).
Umpires: Schmidt, Avon, Nicholls and Keating
Crowd: 8,341 at AAMI Stadium
Dream Team watch -- Matthew Stokes scored 96 Toyota AFL Dream Team points in Geelong's victory over Port Adelaide
The views in this story are those of the author and not necessarily those of the clubs or the AFL.
