GREATER Western Sydney's remarkable first season under first-year coach Adam Kingsley has progressed all the way to a preliminary final, defeating a flat Port Adelaide by 23 points in Saturday night’s Semi-Final.

The 9.16 (70) to 13.15 (93) loss has consigned the Power to an exit from finals after finishing third, while GWS will play its second preliminary final against Collingwood in five years.

Port Adelaide pushed hard in the final term but was its own worst enemy, kicking 1.5 and one out on the full, before Giants skipper Toby Greene pushed the margin out to a safe 27 points with his third goal.

It took until seven minutes into the second quarter for one team to manage successive goals, the Giants jumping out to an eight-point lead after majors to Jesse Hogan and Josh Kelly.

After dominating clearances and uncontested disposals in the first quarter but remaining relatively even on the scoreboard, those two goals opened the floodgates for the orange tsunami.

The Giants were brave and bold, playing with speed and dare through the middle of Adelaide Oval and stunning the parochial home crowd in piling on five straight goals, capped off by a 55m set-shot bomb from Isaac Cumming.

At that point, everything was going so well for the Giants that Sam Taylor managed to deflect a Travis Boak shot with his calf, while facing away from the footy.

GWS left the door open for Port Adelaide, following its five goals with six straight behinds, but the Power could only manage four behinds themselves to trail by 29 points at half-time.

Willie Rioli was comfortably Port Adelaide's most dangerous forward with limited supply, his third goal opening scoring in the second half, while Jason Horne-Francis was creative and Dan Houston steady.

After a quiet first two quarters, Zak Butters burst through to record 11 disposals in the third term, finding some space as the Power began to equalise general play, but they could only trim three points off the margin.

Stephen Coniglio missed last week's elimination final after a poke to the eye at training, but made up for lost time against the Power, recording 22 disposals and a goal in the first half and finishing with 30 and eight clearances.

Callan Ward was crucial in the first half with his disposal inside 50, Lachie Whitfield's pace off half-back kickstarted the Giants' run, while Toby Bedford found space on the wing and across half-forward time and time again.

PORT ADELAIDE                        4.1     5.6         8.7         9.16     (70)

GREATER WESTERN SYDNEY     4.4     9.11     11.15     13.15     (93)

GOALS

Port Adelaide: Rioli 3, Marshall 2, Horne-Francis, Drew, Lord, Dixon

Greater Western Sydney: Hogan 4, Greene 3, Coniglio 2, Daniels, Kelly, Cumming, Riccardi

BEST

Port Adelaide: Horne-Francis, Houston, Rioli, Butters, Boak

Greater Western Sydney: Coniglio, Ward, Briggs, Hogan, Bedford, Whitfield

INJURIES

Port Adelaide: Nil

Greater Western Sydney: Briggs (shoulder)

SUBSTITUTES

Port Adelaide: Jeremy Finlayson (replaced Scott Lycett in the third quarter)

Greater Western Sydney: Xavier O'Halloran (replaced Callum Brown in the fourth quarter)

Crowd: 45,520 at Adelaide Oval