A four-goal haul from Tyson Stengle and an impressive finals debut from emerging star Lawson Humphries guided Geelong to a thumping 84-point win over Port Adelaide in Thursday's qualifying final.

The Cats progress to their 13th preliminary final in the last 18 seasons after running away in the second half to send a warning to the competition and place plenty of questions on the season's second-ranked side before they host a home semi-final next week.

Geelong move on to the third week of finals after winning 20.18 (138) to 7.12 (54) at Adelaide Oval.

The Power etched a one-goal win in the two side's only previous meeting at GMHBA Stadium in round nine.

On Thursday, the visitors led for the vast majority, with Port only edging in front for a moment in the second term - helped set up by forward Willie Rioli.

In his first final since kicking four in Geelong's 2022 grand final triumph, Stengle got his side going, registering the match's first major within three minutes by getting boot to a messy footy in traffic.

He replicated the effort after the first break, crumbing a marking contest and dribbling home to extend a narrow quarter-time lead seconds into play.

Stengle had three before half time, kicking his fourth with the result sewed up after selling some candy and guiding the ball though off the outside of the boot mid-way through the final term.

Speaking post match, Geelong captain Patrick Dangerfield said Stengle was "the best in the business" among small men up front.

In his presser, coach Chris Scott commended their small forwards at large in putting on 20.18 in front of an away crowd.

"If they (Port) intercept and mark the ball, then they look really good. But if the ball hits the ground, then the really good, genuine small forwards look good against anyone," Scott said.

12 months on from a flag-winning WAFL reserves campaign with Swan Districts, Lawson Humphries looked right at home on the main stage.

After debuting mid-way through the year, the 21-year-old was one of six finals debutants in a depleted Geelong line up.

He collected 20 touches and 482 metres gained for the night.

With a laugh after the final siren, Dangerfield told the broadcast Humphries "goes alright off the half back".

For Port Adelaide, Rioli and Jason Horne-Francis looked their side's most dangerous scoring threats, kicking one goal apiece, but failed to make a difference in the Cats' second half onslaught.

The Power face the winner of Saturday's elimination final between Brisbane and Carlton next week.